diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 1153 |
1 files changed, 900 insertions, 253 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 529414556962..dc7ac0c60547 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -33,6 +33,7 @@ #include <drm/drm_fixed.h> #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> +#include <drm/drm_probe_helper.h> /** * DOC: dp mst helper @@ -45,7 +46,7 @@ static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, char *buf); static int test_calc_pbn_mode(void); -static void drm_dp_put_port(struct drm_dp_mst_port *port); +static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port); static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, int id, @@ -66,6 +67,64 @@ static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux); static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux); static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); + +#define DP_STR(x) [DP_ ## x] = #x + +static const char *drm_dp_mst_req_type_str(u8 req_type) +{ + static const char * const req_type_str[] = { + DP_STR(GET_MSG_TRANSACTION_VERSION), + DP_STR(LINK_ADDRESS), + DP_STR(CONNECTION_STATUS_NOTIFY), + DP_STR(ENUM_PATH_RESOURCES), + DP_STR(ALLOCATE_PAYLOAD), + DP_STR(QUERY_PAYLOAD), + DP_STR(RESOURCE_STATUS_NOTIFY), + DP_STR(CLEAR_PAYLOAD_ID_TABLE), + DP_STR(REMOTE_DPCD_READ), + DP_STR(REMOTE_DPCD_WRITE), + DP_STR(REMOTE_I2C_READ), + DP_STR(REMOTE_I2C_WRITE), + DP_STR(POWER_UP_PHY), + DP_STR(POWER_DOWN_PHY), + DP_STR(SINK_EVENT_NOTIFY), + DP_STR(QUERY_STREAM_ENC_STATUS), + }; + + if (req_type >= ARRAY_SIZE(req_type_str) || + !req_type_str[req_type]) + return "unknown"; + + return req_type_str[req_type]; +} + +#undef DP_STR +#define DP_STR(x) [DP_NAK_ ## x] = #x + +static const char *drm_dp_mst_nak_reason_str(u8 nak_reason) +{ + static const char * const nak_reason_str[] = { + DP_STR(WRITE_FAILURE), + DP_STR(INVALID_READ), + DP_STR(CRC_FAILURE), + DP_STR(BAD_PARAM), + DP_STR(DEFER), + DP_STR(LINK_FAILURE), + DP_STR(NO_RESOURCES), + DP_STR(DPCD_FAIL), + DP_STR(I2C_NAK), + DP_STR(ALLOCATE_FAIL), + }; + + if (nak_reason >= ARRAY_SIZE(nak_reason_str) || + !nak_reason_str[nak_reason]) + return "unknown"; + + return nak_reason_str[nak_reason]; +} + +#undef DP_STR + /* sideband msg handling */ static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles) { @@ -567,7 +626,7 @@ static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw, msg->reply_type = (raw->msg[0] & 0x80) >> 7; msg->req_type = (raw->msg[0] & 0x7f); - if (msg->reply_type) { + if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) { memcpy(msg->u.nak.guid, &raw->msg[1], 16); msg->u.nak.reason = raw->msg[17]; msg->u.nak.nak_data = raw->msg[18]; @@ -593,7 +652,8 @@ static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw, case DP_POWER_UP_PHY: return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg); default: - DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type); + DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type, + drm_dp_mst_req_type_str(msg->req_type)); return false; } } @@ -660,7 +720,8 @@ static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw, case DP_RESOURCE_STATUS_NOTIFY: return drm_dp_sideband_parse_resource_status_notify(raw, msg); default: - DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type); + DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type, + drm_dp_mst_req_type_str(msg->req_type)); return false; } } @@ -849,46 +910,212 @@ static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad) if (lct > 1) memcpy(mstb->rad, rad, lct / 2); INIT_LIST_HEAD(&mstb->ports); - kref_init(&mstb->kref); + kref_init(&mstb->topology_kref); + kref_init(&mstb->malloc_kref); return mstb; } -static void drm_dp_free_mst_port(struct kref *kref); - static void drm_dp_free_mst_branch_device(struct kref *kref) { - struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref); - if (mstb->port_parent) { - if (list_empty(&mstb->port_parent->next)) - kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port); - } + struct drm_dp_mst_branch *mstb = + container_of(kref, struct drm_dp_mst_branch, malloc_kref); + + if (mstb->port_parent) + drm_dp_mst_put_port_malloc(mstb->port_parent); + kfree(mstb); } +/** + * DOC: Branch device and port refcounting + * + * Topology refcount overview + * ~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * The refcounting schemes for &struct drm_dp_mst_branch and &struct + * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have + * two different kinds of refcounts: topology refcounts, and malloc refcounts. + * + * Topology refcounts are not exposed to drivers, and are handled internally + * by the DP MST helpers. The helpers use them in order to prevent the + * in-memory topology state from being changed in the middle of critical + * operations like changing the internal state of payload allocations. This + * means each branch and port will be considered to be connected to the rest + * of the topology until its topology refcount reaches zero. Additionally, + * for ports this means that their associated &struct drm_connector will stay + * registered with userspace until the port's refcount reaches 0. + * + * Malloc refcount overview + * ~~~~~~~~~~~~~~~~~~~~~~~~ + * + * Malloc references are used to keep a &struct drm_dp_mst_port or &struct + * drm_dp_mst_branch allocated even after all of its topology references have + * been dropped, so that the driver or MST helpers can safely access each + * branch's last known state before it was disconnected from the topology. + * When the malloc refcount of a port or branch reaches 0, the memory + * allocation containing the &struct drm_dp_mst_branch or &struct + * drm_dp_mst_port respectively will be freed. + * + * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed + * to drivers. As of writing this documentation, there are no drivers that + * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST + * helpers. Exposing this API to drivers in a race-free manner would take more + * tweaking of the refcounting scheme, however patches are welcome provided + * there is a legitimate driver usecase for this. + * + * Refcount relationships in a topology + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * Let's take a look at why the relationship between topology and malloc + * refcounts is designed the way it is. + * + * .. kernel-figure:: dp-mst/topology-figure-1.dot + * + * An example of topology and malloc refs in a DP MST topology with two + * active payloads. Topology refcount increments are indicated by solid + * lines, and malloc refcount increments are indicated by dashed lines. + * Each starts from the branch which incremented the refcount, and ends at + * the branch to which the refcount belongs to, i.e. the arrow points the + * same way as the C pointers used to reference a structure. + * + * As you can see in the above figure, every branch increments the topology + * refcount of its children, and increments the malloc refcount of its + * parent. Additionally, every payload increments the malloc refcount of its + * assigned port by 1. + * + * So, what would happen if MSTB #3 from the above figure was unplugged from + * the system, but the driver hadn't yet removed payload #2 from port #3? The + * topology would start to look like the figure below. + * + * .. kernel-figure:: dp-mst/topology-figure-2.dot + * + * Ports and branch devices which have been released from memory are + * colored grey, and references which have been removed are colored red. + * + * Whenever a port or branch device's topology refcount reaches zero, it will + * decrement the topology refcounts of all its children, the malloc refcount + * of its parent, and finally its own malloc refcount. For MSTB #4 and port + * #4, this means they both have been disconnected from the topology and freed + * from memory. But, because payload #2 is still holding a reference to port + * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port + * is still accessible from memory. This also means port #3 has not yet + * decremented the malloc refcount of MSTB #3, so its &struct + * drm_dp_mst_branch will also stay allocated in memory until port #3's + * malloc refcount reaches 0. + * + * This relationship is necessary because in order to release payload #2, we + * need to be able to figure out the last relative of port #3 that's still + * connected to the topology. In this case, we would travel up the topology as + * shown below. + * + * .. kernel-figure:: dp-mst/topology-figure-3.dot + * + * And finally, remove payload #2 by communicating with port #2 through + * sideband transactions. + */ + +/** + * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch + * device + * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of + * + * Increments &drm_dp_mst_branch.malloc_kref. When + * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb + * will be released and @mstb may no longer be used. + * + * See also: drm_dp_mst_put_mstb_malloc() + */ +static void +drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb) +{ + kref_get(&mstb->malloc_kref); + DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref)); +} + +/** + * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch + * device + * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of + * + * Decrements &drm_dp_mst_branch.malloc_kref. When + * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb + * will be released and @mstb may no longer be used. + * + * See also: drm_dp_mst_get_mstb_malloc() + */ +static void +drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb) +{ + DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1); + kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device); +} + +static void drm_dp_free_mst_port(struct kref *kref) +{ + struct drm_dp_mst_port *port = + container_of(kref, struct drm_dp_mst_port, malloc_kref); + + drm_dp_mst_put_mstb_malloc(port->parent); + kfree(port); +} + +/** + * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port + * @port: The &struct drm_dp_mst_port to increment the malloc refcount of + * + * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref + * reaches 0, the memory allocation for @port will be released and @port may + * no longer be used. + * + * Because @port could potentially be freed at any time by the DP MST helpers + * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this + * function, drivers that which to make use of &struct drm_dp_mst_port should + * ensure that they grab at least one main malloc reference to their MST ports + * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before + * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0. + * + * See also: drm_dp_mst_put_port_malloc() + */ +void +drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port) +{ + kref_get(&port->malloc_kref); + DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref)); +} +EXPORT_SYMBOL(drm_dp_mst_get_port_malloc); + +/** + * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port + * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of + * + * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref + * reaches 0, the memory allocation for @port will be released and @port may + * no longer be used. + * + * See also: drm_dp_mst_get_port_malloc() + */ +void +drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port) +{ + DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1); + kref_put(&port->malloc_kref, drm_dp_free_mst_port); +} +EXPORT_SYMBOL(drm_dp_mst_put_port_malloc); + static void drm_dp_destroy_mst_branch_device(struct kref *kref) { - struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref); + struct drm_dp_mst_branch *mstb = + container_of(kref, struct drm_dp_mst_branch, topology_kref); + struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; struct drm_dp_mst_port *port, *tmp; bool wake_tx = false; - /* - * init kref again to be used by ports to remove mst branch when it is - * not needed anymore - */ - kref_init(kref); - - if (mstb->port_parent && list_empty(&mstb->port_parent->next)) - kref_get(&mstb->port_parent->kref); - - /* - * destroy all ports - don't need lock - * as there are no more references to the mst branch - * device at this point. - */ + mutex_lock(&mgr->lock); list_for_each_entry_safe(port, tmp, &mstb->ports, next) { list_del(&port->next); - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); } + mutex_unlock(&mgr->lock); /* drop any tx slots msg */ mutex_lock(&mstb->mgr->qlock); @@ -907,14 +1134,83 @@ static void drm_dp_destroy_mst_branch_device(struct kref *kref) if (wake_tx) wake_up_all(&mstb->mgr->tx_waitq); - kref_put(kref, drm_dp_free_mst_branch_device); + drm_dp_mst_put_mstb_malloc(mstb); } -static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb) +/** + * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a + * branch device unless it's zero + * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of + * + * Attempts to grab a topology reference to @mstb, if it hasn't yet been + * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has + * reached 0). Holding a topology reference implies that a malloc reference + * will be held to @mstb as long as the user holds the topology reference. + * + * Care should be taken to ensure that the user has at least one malloc + * reference to @mstb. If you already have a topology reference to @mstb, you + * should use drm_dp_mst_topology_get_mstb() instead. + * + * See also: + * drm_dp_mst_topology_get_mstb() + * drm_dp_mst_topology_put_mstb() + * + * Returns: + * * 1: A topology reference was grabbed successfully + * * 0: @port is no longer in the topology, no reference was grabbed + */ +static int __must_check +drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb) { - kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device); + int ret = kref_get_unless_zero(&mstb->topology_kref); + + if (ret) + DRM_DEBUG("mstb %p (%d)\n", mstb, + kref_read(&mstb->topology_kref)); + + return ret; } +/** + * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a + * branch device + * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of + * + * Increments &drm_dp_mst_branch.topology_refcount without checking whether or + * not it's already reached 0. This is only valid to use in scenarios where + * you are already guaranteed to have at least one active topology reference + * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used. + * + * See also: + * drm_dp_mst_topology_try_get_mstb() + * drm_dp_mst_topology_put_mstb() + */ +static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb) +{ + WARN_ON(kref_read(&mstb->topology_kref) == 0); + kref_get(&mstb->topology_kref); + DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); +} + +/** + * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch + * device + * @mstb: The &struct drm_dp_mst_branch to release the topology reference from + * + * Releases a topology reference from @mstb by decrementing + * &drm_dp_mst_branch.topology_kref. + * + * See also: + * drm_dp_mst_topology_try_get_mstb() + * drm_dp_mst_topology_get_mstb() + */ +static void +drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb) +{ + DRM_DEBUG("mstb %p (%d)\n", + mstb, kref_read(&mstb->topology_kref) - 1); + kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device); +} static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt) { @@ -929,19 +1225,18 @@ static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt) case DP_PEER_DEVICE_MST_BRANCHING: mstb = port->mstb; port->mstb = NULL; - drm_dp_put_mst_branch_device(mstb); + drm_dp_mst_topology_put_mstb(mstb); break; } } static void drm_dp_destroy_port(struct kref *kref) { - struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref); + struct drm_dp_mst_port *port = + container_of(kref, struct drm_dp_mst_port, topology_kref); struct drm_dp_mst_topology_mgr *mgr = port->mgr; if (!port->input) { - port->vcpi.num_slots = 0; - kfree(port->cached_edid); /* @@ -955,7 +1250,6 @@ static void drm_dp_destroy_port(struct kref *kref) * from an EDID retrieval */ mutex_lock(&mgr->destroy_connector_lock); - kref_get(&port->parent->kref); list_add(&port->next, &mgr->destroy_connector_list); mutex_unlock(&mgr->destroy_connector_lock); schedule_work(&mgr->destroy_connector_work); @@ -966,25 +1260,95 @@ static void drm_dp_destroy_port(struct kref *kref) drm_dp_port_teardown_pdt(port, port->pdt); port->pdt = DP_PEER_DEVICE_NONE; } - kfree(port); + drm_dp_mst_put_port_malloc(port); } -static void drm_dp_put_port(struct drm_dp_mst_port *port) +/** + * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a + * port unless it's zero + * @port: &struct drm_dp_mst_port to increment the topology refcount of + * + * Attempts to grab a topology reference to @port, if it hasn't yet been + * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached + * 0). Holding a topology reference implies that a malloc reference will be + * held to @port as long as the user holds the topology reference. + * + * Care should be taken to ensure that the user has at least one malloc + * reference to @port. If you already have a topology reference to @port, you + * should use drm_dp_mst_topology_get_port() instead. + * + * See also: + * drm_dp_mst_topology_get_port() + * drm_dp_mst_topology_put_port() + * + * Returns: + * * 1: A topology reference was grabbed successfully + * * 0: @port is no longer in the topology, no reference was grabbed + */ +static int __must_check +drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port) { - kref_put(&port->kref, drm_dp_destroy_port); + int ret = kref_get_unless_zero(&port->topology_kref); + + if (ret) + DRM_DEBUG("port %p (%d)\n", port, + kref_read(&port->topology_kref)); + + return ret; } -static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find) +/** + * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port + * @port: The &struct drm_dp_mst_port to increment the topology refcount of + * + * Increments &drm_dp_mst_port.topology_refcount without checking whether or + * not it's already reached 0. This is only valid to use in scenarios where + * you are already guaranteed to have at least one active topology reference + * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used. + * + * See also: + * drm_dp_mst_topology_try_get_port() + * drm_dp_mst_topology_put_port() + */ +static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port) +{ + WARN_ON(kref_read(&port->topology_kref) == 0); + kref_get(&port->topology_kref); + DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref)); +} + +/** + * drm_dp_mst_topology_put_port() - release a topology reference to a port + * @port: The &struct drm_dp_mst_port to release the topology reference from + * + * Releases a topology reference from @port by decrementing + * &drm_dp_mst_port.topology_kref. + * + * See also: + * drm_dp_mst_topology_try_get_port() + * drm_dp_mst_topology_get_port() + */ +static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port) +{ + DRM_DEBUG("port %p (%d)\n", + port, kref_read(&port->topology_kref) - 1); + kref_put(&port->topology_kref, drm_dp_destroy_port); +} + +static struct drm_dp_mst_branch * +drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb, + struct drm_dp_mst_branch *to_find) { struct drm_dp_mst_port *port; struct drm_dp_mst_branch *rmstb; - if (to_find == mstb) { - kref_get(&mstb->kref); + + if (to_find == mstb) return mstb; - } + list_for_each_entry(port, &mstb->ports, next) { if (port->mstb) { - rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find); + rmstb = drm_dp_mst_topology_get_mstb_validated_locked( + port->mstb, to_find); if (rmstb) return rmstb; } @@ -992,27 +1356,37 @@ static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct return NULL; } -static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb) +static struct drm_dp_mst_branch * +drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_branch *rmstb = NULL; + mutex_lock(&mgr->lock); - if (mgr->mst_primary) - rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb); + if (mgr->mst_primary) { + rmstb = drm_dp_mst_topology_get_mstb_validated_locked( + mgr->mst_primary, mstb); + + if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb)) + rmstb = NULL; + } mutex_unlock(&mgr->lock); return rmstb; } -static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find) +static struct drm_dp_mst_port * +drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb, + struct drm_dp_mst_port *to_find) { struct drm_dp_mst_port *port, *mport; list_for_each_entry(port, &mstb->ports, next) { - if (port == to_find) { - kref_get(&port->kref); + if (port == to_find) return port; - } + if (port->mstb) { - mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find); + mport = drm_dp_mst_topology_get_port_validated_locked( + port->mstb, to_find); if (mport) return mport; } @@ -1020,12 +1394,20 @@ static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_ return NULL; } -static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) +static struct drm_dp_mst_port * +drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port) { struct drm_dp_mst_port *rport = NULL; + mutex_lock(&mgr->lock); - if (mgr->mst_primary) - rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port); + if (mgr->mst_primary) { + rport = drm_dp_mst_topology_get_port_validated_locked( + mgr->mst_primary, port); + + if (rport && !drm_dp_mst_topology_try_get_port(rport)) + rport = NULL; + } mutex_unlock(&mgr->lock); return rport; } @@ -1033,11 +1415,12 @@ static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_t static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num) { struct drm_dp_mst_port *port; + int ret; list_for_each_entry(port, &mstb->ports, next) { if (port->port_num == port_num) { - kref_get(&port->kref); - return port; + ret = drm_dp_mst_topology_try_get_port(port); + return ret ? port : NULL; } } @@ -1086,6 +1469,11 @@ static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port) if (port->mstb) { port->mstb->mgr = port->mgr; port->mstb->port_parent = port; + /* + * Make sure this port's memory allocation stays + * around until its child MSTB releases it + */ + drm_dp_mst_get_port_malloc(port); send_link = true; } @@ -1146,17 +1534,26 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, bool created = false; int old_pdt = 0; int old_ddps = 0; + port = drm_dp_get_port(mstb, port_msg->port_number); if (!port) { port = kzalloc(sizeof(*port), GFP_KERNEL); if (!port) return; - kref_init(&port->kref); + kref_init(&port->topology_kref); + kref_init(&port->malloc_kref); port->parent = mstb; port->port_num = port_msg->port_number; port->mgr = mstb->mgr; port->aux.name = "DPMST"; port->aux.dev = dev->dev; + + /* + * Make sure the memory allocation for our parent branch stays + * around until our own memory allocation is released + */ + drm_dp_mst_get_mstb_malloc(mstb); + created = true; } else { old_pdt = port->pdt; @@ -1176,18 +1573,20 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, for this list */ if (created) { mutex_lock(&mstb->mgr->lock); - kref_get(&port->kref); + drm_dp_mst_topology_get_port(port); list_add(&port->next, &mstb->ports); mutex_unlock(&mstb->mgr->lock); } if (old_ddps != port->ddps) { if (port->ddps) { - if (!port->input) - drm_dp_send_enum_path_resources(mstb->mgr, mstb, port); + if (!port->input) { + drm_dp_send_enum_path_resources(mstb->mgr, + mstb, port); + } } else { port->available_pbn = 0; - } + } } if (old_pdt != port->pdt && !port->input) { @@ -1201,21 +1600,25 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, if (created && !port->input) { char proppath[255]; - build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); - port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath); + build_mst_prop_path(mstb, port->port_num, proppath, + sizeof(proppath)); + port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, + port, + proppath); if (!port->connector) { /* remove it from the port list */ mutex_lock(&mstb->mgr->lock); list_del(&port->next); mutex_unlock(&mstb->mgr->lock); /* drop port list reference */ - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); goto out; } if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV || port->pdt == DP_PEER_DEVICE_SST_SINK) && port->port_num >= DP_MST_LOGICAL_PORT_0) { - port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc); + port->cached_edid = drm_get_edid(port->connector, + &port->aux.ddc); drm_connector_set_tile_property(port->connector); } (*mstb->mgr->cbs->register_connector)(port->connector); @@ -1223,7 +1626,7 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, out: /* put reference to this port */ - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); } static void drm_dp_update_port(struct drm_dp_mst_branch *mstb, @@ -1258,7 +1661,7 @@ static void drm_dp_update_port(struct drm_dp_mst_branch *mstb, dowork = true; } - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); if (dowork) queue_work(system_long_wq, &mstb->mgr->work); @@ -1269,7 +1672,7 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_ { struct drm_dp_mst_branch *mstb; struct drm_dp_mst_port *port; - int i; + int i, ret; /* find the port by iterating down */ mutex_lock(&mgr->lock); @@ -1294,7 +1697,9 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_ } } } - kref_get(&mstb->kref); + ret = drm_dp_mst_topology_try_get_mstb(mstb); + if (!ret) + mstb = NULL; out: mutex_unlock(&mgr->lock); return mstb; @@ -1324,19 +1729,22 @@ static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper( return NULL; } -static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid( - struct drm_dp_mst_topology_mgr *mgr, - uint8_t *guid) +static struct drm_dp_mst_branch * +drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr, + uint8_t *guid) { struct drm_dp_mst_branch *mstb; + int ret; /* find the port by iterating down */ mutex_lock(&mgr->lock); mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid); - - if (mstb) - kref_get(&mstb->kref); + if (mstb) { + ret = drm_dp_mst_topology_try_get_mstb(mstb); + if (!ret) + mstb = NULL; + } mutex_unlock(&mgr->lock); return mstb; @@ -1361,10 +1769,11 @@ static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *m drm_dp_send_enum_path_resources(mgr, mstb, port); if (port->mstb) { - mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb); + mstb_child = drm_dp_mst_topology_get_mstb_validated( + mgr, port->mstb); if (mstb_child) { drm_dp_check_and_send_link_address(mgr, mstb_child); - drm_dp_put_mst_branch_device(mstb_child); + drm_dp_mst_topology_put_mstb(mstb_child); } } } @@ -1374,16 +1783,19 @@ static void drm_dp_mst_link_probe_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work); struct drm_dp_mst_branch *mstb; + int ret; mutex_lock(&mgr->lock); mstb = mgr->mst_primary; if (mstb) { - kref_get(&mstb->kref); + ret = drm_dp_mst_topology_try_get_mstb(mstb); + if (!ret) + mstb = NULL; } mutex_unlock(&mgr->lock); if (mstb) { drm_dp_check_and_send_link_address(mgr, mstb); - drm_dp_put_mst_branch_device(mstb); + drm_dp_mst_topology_put_mstb(mstb); } } @@ -1617,9 +2029,9 @@ static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, if (ret > 0) { int i; - if (txmsg->reply.reply_type == 1) + if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { DRM_DEBUG_KMS("link address nak received\n"); - else { + } else { DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports); for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) { DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i, @@ -1639,7 +2051,7 @@ static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) { drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]); } - (*mgr->cbs->hotplug)(mgr); + drm_kms_helper_hotplug_event(mgr->dev); } } else { mstb->link_address_sent = false; @@ -1668,9 +2080,9 @@ static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { - if (txmsg->reply.reply_type == 1) + if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { DRM_DEBUG_KMS("enum path resources nak received\n"); - else { + } else { if (port->port_num != txmsg->reply.u.path_resources.port_number) DRM_ERROR("got incorrect port in response\n"); DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number, @@ -1694,22 +2106,40 @@ static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); } -static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, - struct drm_dp_mst_branch *mstb, - int *port_num) +/* + * Searches upwards in the topology starting from mstb to try to find the + * closest available parent of mstb that's still connected to the rest of the + * topology. This can be used in order to perform operations like releasing + * payloads, where the branch device which owned the payload may no longer be + * around and thus would require that the payload on the last living relative + * be freed instead. + */ +static struct drm_dp_mst_branch * +drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_branch *mstb, + int *port_num) { struct drm_dp_mst_branch *rmstb = NULL; struct drm_dp_mst_port *found_port; + mutex_lock(&mgr->lock); - if (mgr->mst_primary) { + if (!mgr->mst_primary) + goto out; + + do { found_port = drm_dp_get_last_connected_port_to_mstb(mstb); + if (!found_port) + break; - if (found_port) { + if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) { rmstb = found_port->parent; - kref_get(&rmstb->kref); *port_num = found_port->port_num; + } else { + /* Search again, starting from this parent */ + mstb = found_port->parent; } - } + } while (!rmstb); +out: mutex_unlock(&mgr->lock); return rmstb; } @@ -1725,19 +2155,15 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, u8 sinks[DRM_DP_MAX_SDP_STREAMS]; int i; - port = drm_dp_get_validated_port_ref(mgr, port); - if (!port) - return -EINVAL; - port_num = port->port_num; - mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); + mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); if (!mstb) { - mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num); + mstb = drm_dp_get_last_connected_port_and_mstb(mgr, + port->parent, + &port_num); - if (!mstb) { - drm_dp_put_port(port); + if (!mstb) return -EINVAL; - } } txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); @@ -1756,17 +2182,24 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, drm_dp_queue_down_tx(mgr, txmsg); + /* + * FIXME: there is a small chance that between getting the last + * connected mstb and sending the payload message, the last connected + * mstb could also be removed from the topology. In the future, this + * needs to be fixed by restarting the + * drm_dp_get_last_connected_port_and_mstb() search in the event of a + * timeout if the topology is still connected to the system. + */ ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { - if (txmsg->reply.reply_type == 1) { + if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) ret = -EINVAL; - } else + else ret = 0; } kfree(txmsg); fail_put: - drm_dp_put_mst_branch_device(mstb); - drm_dp_put_port(port); + drm_dp_mst_topology_put_mstb(mstb); return ret; } @@ -1776,13 +2209,13 @@ int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_sideband_msg_tx *txmsg; int len, ret; - port = drm_dp_get_validated_port_ref(mgr, port); + port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return -EINVAL; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); if (!txmsg) { - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); return -ENOMEM; } @@ -1792,13 +2225,13 @@ int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg); if (ret > 0) { - if (txmsg->reply.reply_type == 1) + if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) ret = -EINVAL; else ret = 0; } kfree(txmsg); - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); return ret; } @@ -1838,7 +2271,7 @@ static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_payload *payload) { DRM_DEBUG_KMS("\n"); - /* its okay for these to fail */ + /* it's okay for these to fail */ if (port) { drm_dp_payload_send_msg(mgr, port, id, 0); } @@ -1871,72 +2304,93 @@ static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr, */ int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr) { - int i, j; - int cur_slots = 1; struct drm_dp_payload req_payload; struct drm_dp_mst_port *port; + int i, j; + int cur_slots = 1; mutex_lock(&mgr->payload_lock); for (i = 0; i < mgr->max_payloads; i++) { + struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i]; + struct drm_dp_payload *payload = &mgr->payloads[i]; + bool put_port = false; + /* solve the current payloads - compare to the hw ones - update the hw view */ req_payload.start_slot = cur_slots; - if (mgr->proposed_vcpis[i]) { - port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); - port = drm_dp_get_validated_port_ref(mgr, port); - if (!port) { - mutex_unlock(&mgr->payload_lock); - return -EINVAL; + if (vcpi) { + port = container_of(vcpi, struct drm_dp_mst_port, + vcpi); + + /* Validated ports don't matter if we're releasing + * VCPI + */ + if (vcpi->num_slots) { + port = drm_dp_mst_topology_get_port_validated( + mgr, port); + if (!port) { + mutex_unlock(&mgr->payload_lock); + return -EINVAL; + } + put_port = true; } - req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots; - req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi; + + req_payload.num_slots = vcpi->num_slots; + req_payload.vcpi = vcpi->vcpi; } else { port = NULL; req_payload.num_slots = 0; } - if (mgr->payloads[i].start_slot != req_payload.start_slot) { - mgr->payloads[i].start_slot = req_payload.start_slot; - } + payload->start_slot = req_payload.start_slot; /* work out what is required to happen with this payload */ - if (mgr->payloads[i].num_slots != req_payload.num_slots) { + if (payload->num_slots != req_payload.num_slots) { /* need to push an update for this payload */ if (req_payload.num_slots) { - drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload); - mgr->payloads[i].num_slots = req_payload.num_slots; - mgr->payloads[i].vcpi = req_payload.vcpi; - } else if (mgr->payloads[i].num_slots) { - mgr->payloads[i].num_slots = 0; - drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]); - req_payload.payload_state = mgr->payloads[i].payload_state; - mgr->payloads[i].start_slot = 0; + drm_dp_create_payload_step1(mgr, vcpi->vcpi, + &req_payload); + payload->num_slots = req_payload.num_slots; + payload->vcpi = req_payload.vcpi; + + } else if (payload->num_slots) { + payload->num_slots = 0; + drm_dp_destroy_payload_step1(mgr, port, + payload->vcpi, + payload); + req_payload.payload_state = + payload->payload_state; + payload->start_slot = 0; } - mgr->payloads[i].payload_state = req_payload.payload_state; + payload->payload_state = req_payload.payload_state; } cur_slots += req_payload.num_slots; - if (port) - drm_dp_put_port(port); + if (put_port) + drm_dp_mst_topology_put_port(port); } for (i = 0; i < mgr->max_payloads; i++) { - if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) { - DRM_DEBUG_KMS("removing payload %d\n", i); - for (j = i; j < mgr->max_payloads - 1; j++) { - memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload)); - mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1]; - if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) { - set_bit(j + 1, &mgr->payload_mask); - } else { - clear_bit(j + 1, &mgr->payload_mask); - } - } - memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload)); - mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL; - clear_bit(mgr->max_payloads, &mgr->payload_mask); + if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) + continue; + DRM_DEBUG_KMS("removing payload %d\n", i); + for (j = i; j < mgr->max_payloads - 1; j++) { + mgr->payloads[j] = mgr->payloads[j + 1]; + mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1]; + + if (mgr->proposed_vcpis[j] && + mgr->proposed_vcpis[j]->num_slots) { + set_bit(j + 1, &mgr->payload_mask); + } else { + clear_bit(j + 1, &mgr->payload_mask); + } } + + memset(&mgr->payloads[mgr->max_payloads - 1], 0, + sizeof(struct drm_dp_payload)); + mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL; + clear_bit(mgr->max_payloads, &mgr->payload_mask); } mutex_unlock(&mgr->payload_lock); @@ -2012,7 +2466,7 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_sideband_msg_tx *txmsg; struct drm_dp_mst_branch *mstb; - mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); + mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); if (!mstb) return -EINVAL; @@ -2029,14 +2483,14 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { - if (txmsg->reply.reply_type == 1) { + if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) ret = -EINVAL; - } else + else ret = 0; } kfree(txmsg); fail_put: - drm_dp_put_mst_branch_device(mstb); + drm_dp_mst_topology_put_mstb(mstb); return ret; } @@ -2044,7 +2498,7 @@ static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req { struct drm_dp_sideband_msg_reply_body reply; - reply.reply_type = 0; + reply.reply_type = DP_SIDEBAND_REPLY_ACK; reply.req_type = req_type; drm_dp_encode_sideband_reply(&reply, msg); return 0; @@ -2146,7 +2600,7 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms /* give this the main reference */ mgr->mst_primary = mstb; - kref_get(&mgr->mst_primary->kref); + drm_dp_mst_topology_get_mstb(mgr->mst_primary); ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); @@ -2180,7 +2634,7 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms out_unlock: mutex_unlock(&mgr->lock); if (mstb) - drm_dp_put_mst_branch_device(mstb); + drm_dp_mst_topology_put_mstb(mstb); return ret; } @@ -2345,18 +2799,23 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) mgr->down_rep_recv.initial_hdr.lct, mgr->down_rep_recv.initial_hdr.rad[0], mgr->down_rep_recv.msg[0]); - drm_dp_put_mst_branch_device(mstb); + drm_dp_mst_topology_put_mstb(mstb); memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); return 0; } drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply); - if (txmsg->reply.reply_type == 1) { - DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data); - } + + if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) + DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n", + txmsg->reply.req_type, + drm_dp_mst_req_type_str(txmsg->reply.req_type), + txmsg->reply.u.nak.reason, + drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason), + txmsg->reply.u.nak.nak_data); memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); - drm_dp_put_mst_branch_device(mstb); + drm_dp_mst_topology_put_mstb(mstb); mutex_lock(&mgr->qlock); txmsg->state = DRM_DP_SIDEBAND_TX_RX; @@ -2412,7 +2871,7 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) drm_dp_update_port(mstb, &msg.u.conn_stat); DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type); - (*mgr->cbs->hotplug)(mgr); + drm_kms_helper_hotplug_event(mgr->dev); } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false); @@ -2429,7 +2888,7 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) } if (mstb) - drm_dp_put_mst_branch_device(mstb); + drm_dp_mst_topology_put_mstb(mstb); memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); } @@ -2488,8 +2947,8 @@ enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector { enum drm_connector_status status = connector_status_disconnected; - /* we need to search for the port in the mgr in case its gone */ - port = drm_dp_get_validated_port_ref(mgr, port); + /* we need to search for the port in the mgr in case it's gone */ + port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return connector_status_disconnected; @@ -2514,7 +2973,7 @@ enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector break; } out: - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); return status; } EXPORT_SYMBOL(drm_dp_mst_detect_port); @@ -2531,11 +2990,11 @@ bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr, { bool ret = false; - port = drm_dp_get_validated_port_ref(mgr, port); + port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return ret; ret = port->has_audio; - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); return ret; } EXPORT_SYMBOL(drm_dp_mst_port_has_audio); @@ -2554,8 +3013,8 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_ { struct edid *edid = NULL; - /* we need to search for the port in the mgr in case its gone */ - port = drm_dp_get_validated_port_ref(mgr, port); + /* we need to search for the port in the mgr in case it's gone */ + port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return NULL; @@ -2566,7 +3025,7 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_ drm_connector_set_tile_property(connector); } port->has_audio = drm_detect_monitor_audio(edid); - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); return edid; } EXPORT_SYMBOL(drm_dp_mst_get_edid); @@ -2617,43 +3076,90 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, } /** - * drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state + * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state * @state: global atomic state * @mgr: MST topology manager for the port * @port: port to find vcpi slots for * @pbn: bandwidth required for the mode in PBN * - * RETURNS: - * Total slots in the atomic state assigned for this port or error + * Allocates VCPI slots to @port, replacing any previous VCPI allocations it + * may have had. Any atomic drivers which support MST must call this function + * in their &drm_encoder_helper_funcs.atomic_check() callback to change the + * current VCPI allocation for the new state, but only when + * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set + * to ensure compatibility with userspace applications that still use the + * legacy modesetting UAPI. + * + * Allocations set by this function are not checked against the bandwidth + * restraints of @mgr until the driver calls drm_dp_mst_atomic_check(). + * + * Additionally, it is OK to call this function multiple times on the same + * @port as needed. It is not OK however, to call this function and + * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase. + * + * See also: + * drm_dp_atomic_release_vcpi_slots() + * drm_dp_mst_atomic_check() + * + * Returns: + * Total slots in the atomic state assigned for this port, or a negative error + * code if the port no longer exists */ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn) { struct drm_dp_mst_topology_state *topology_state; - int req_slots; + struct drm_dp_vcpi_allocation *pos, *vcpi = NULL; + int prev_slots, req_slots, ret; topology_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(topology_state)) return PTR_ERR(topology_state); - port = drm_dp_get_validated_port_ref(mgr, port); - if (port == NULL) - return -EINVAL; - req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); - DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n", - req_slots, topology_state->avail_slots); + /* Find the current allocation for this port, if any */ + list_for_each_entry(pos, &topology_state->vcpis, next) { + if (pos->port == port) { + vcpi = pos; + prev_slots = vcpi->vcpi; + + /* + * This should never happen, unless the driver tries + * releasing and allocating the same VCPI allocation, + * which is an error + */ + if (WARN_ON(!prev_slots)) { + DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n", + port); + return -EINVAL; + } - if (req_slots > topology_state->avail_slots) { - drm_dp_put_port(port); - return -ENOSPC; + break; + } } + if (!vcpi) + prev_slots = 0; - topology_state->avail_slots -= req_slots; - DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots); + req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); + + DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n", + port->connector->base.id, port->connector->name, + port, prev_slots, req_slots); + + /* Add the new allocation to the state */ + if (!vcpi) { + vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL); + if (!vcpi) + return -ENOMEM; + + drm_dp_mst_get_port_malloc(port); + vcpi->port = port; + list_add(&vcpi->next, &topology_state->vcpis); + } + vcpi->vcpi = req_slots; - drm_dp_put_port(port); - return req_slots; + ret = req_slots; + return ret; } EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots); @@ -2661,31 +3167,57 @@ EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots); * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots * @state: global atomic state * @mgr: MST topology manager for the port - * @slots: number of vcpi slots to release + * @port: The port to release the VCPI slots from * - * RETURNS: - * 0 if @slots were added back to &drm_dp_mst_topology_state->avail_slots or - * negative error code + * Releases any VCPI slots that have been allocated to a port in the atomic + * state. Any atomic drivers which support MST must call this function in + * their &drm_connector_helper_funcs.atomic_check() callback when the + * connector will no longer have VCPI allocated (e.g. because its CRTC was + * removed) when it had VCPI allocated in the previous atomic state. + * + * It is OK to call this even if @port has been removed from the system. + * Additionally, it is OK to call this function multiple times on the same + * @port as needed. It is not OK however, to call this function and + * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check + * phase. + * + * See also: + * drm_dp_atomic_find_vcpi_slots() + * drm_dp_mst_atomic_check() + * + * Returns: + * 0 if all slots for this port were added back to + * &drm_dp_mst_topology_state.avail_slots or negative error code */ int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, - int slots) + struct drm_dp_mst_port *port) { struct drm_dp_mst_topology_state *topology_state; + struct drm_dp_vcpi_allocation *pos; + bool found = false; topology_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(topology_state)) return PTR_ERR(topology_state); - /* We cannot rely on port->vcpi.num_slots to update - * topology_state->avail_slots as the port may not exist if the parent - * branch device was unplugged. This should be fixed by tracking - * per-port slot allocation in drm_dp_mst_topology_state instead of - * depending on the caller to tell us how many slots to release. - */ - topology_state->avail_slots += slots; - DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n", - slots, topology_state->avail_slots); + list_for_each_entry(pos, &topology_state->vcpis, next) { + if (pos->port == port) { + found = true; + break; + } + } + if (WARN_ON(!found)) { + DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n", + port, &topology_state->base); + return -EINVAL; + } + + DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi); + if (pos->vcpi) { + drm_dp_mst_put_port_malloc(port); + pos->vcpi = 0; + } return 0; } @@ -2703,7 +3235,7 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, { int ret; - port = drm_dp_get_validated_port_ref(mgr, port); + port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return false; @@ -2711,9 +3243,10 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, return false; if (port->vcpi.vcpi > 0) { - DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn); + DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", + port->vcpi.vcpi, port->vcpi.pbn, pbn); if (pbn == port->vcpi.pbn) { - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); return true; } } @@ -2721,13 +3254,15 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots); if (ret) { DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n", - DIV_ROUND_UP(pbn, mgr->pbn_div), ret); + DIV_ROUND_UP(pbn, mgr->pbn_div), ret); goto out; } DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n", - pbn, port->vcpi.num_slots); + pbn, port->vcpi.num_slots); - drm_dp_put_port(port); + /* Keep port allocated until its payload has been removed */ + drm_dp_mst_get_port_malloc(port); + drm_dp_mst_topology_put_port(port); return true; out: return false; @@ -2737,12 +3272,12 @@ EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi); int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { int slots = 0; - port = drm_dp_get_validated_port_ref(mgr, port); + port = drm_dp_mst_topology_get_port_validated(mgr, port); if (!port) return slots; slots = port->vcpi.num_slots; - drm_dp_put_port(port); + drm_dp_mst_topology_put_port(port); return slots; } EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots); @@ -2756,23 +3291,27 @@ EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots); */ void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { - port = drm_dp_get_validated_port_ref(mgr, port); - if (!port) - return; + /* + * A port with VCPI will remain allocated until its VCPI is + * released, no verified ref needed + */ + port->vcpi.num_slots = 0; - drm_dp_put_port(port); } EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots); /** * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI * @mgr: manager for this port - * @port: unverified port to deallocate vcpi for + * @port: port to deallocate vcpi for + * + * This can be called unconditionally, regardless of whether + * drm_dp_mst_allocate_vcpi() succeeded or not. */ -void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) +void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port) { - port = drm_dp_get_validated_port_ref(mgr, port); - if (!port) + if (!port->vcpi.vcpi) return; drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); @@ -2780,7 +3319,7 @@ void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_ port->vcpi.pbn = 0; port->vcpi.aligned_pbn = 0; port->vcpi.vcpi = 0; - drm_dp_put_port(port); + drm_dp_mst_put_port_malloc(port); } EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi); @@ -3064,13 +3603,6 @@ static void drm_dp_tx_work(struct work_struct *work) mutex_unlock(&mgr->qlock); } -static void drm_dp_free_mst_port(struct kref *kref) -{ - struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref); - kref_put(&port->parent->kref, drm_dp_free_mst_branch_device); - kfree(port); -} - static void drm_dp_destroy_connector_work(struct work_struct *work) { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work); @@ -3091,7 +3623,6 @@ static void drm_dp_destroy_connector_work(struct work_struct *work) list_del(&port->next); mutex_unlock(&mgr->destroy_connector_lock); - kref_init(&port->kref); INIT_LIST_HEAD(&port->next); mgr->cbs->destroy_connector(mgr, port->connector); @@ -3099,31 +3630,51 @@ static void drm_dp_destroy_connector_work(struct work_struct *work) drm_dp_port_teardown_pdt(port, port->pdt); port->pdt = DP_PEER_DEVICE_NONE; - if (!port->input && port->vcpi.vcpi > 0) { - drm_dp_mst_reset_vcpi_slots(mgr, port); - drm_dp_update_payload_part1(mgr); - drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); - } - - kref_put(&port->kref, drm_dp_free_mst_port); + drm_dp_mst_put_port_malloc(port); send_hotplug = true; } if (send_hotplug) - (*mgr->cbs->hotplug)(mgr); + drm_kms_helper_hotplug_event(mgr->dev); } static struct drm_private_state * drm_dp_mst_duplicate_state(struct drm_private_obj *obj) { - struct drm_dp_mst_topology_state *state; + struct drm_dp_mst_topology_state *state, *old_state = + to_dp_mst_topology_state(obj->state); + struct drm_dp_vcpi_allocation *pos, *vcpi; - state = kmemdup(obj->state, sizeof(*state), GFP_KERNEL); + state = kmemdup(old_state, sizeof(*state), GFP_KERNEL); if (!state) return NULL; __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base); + INIT_LIST_HEAD(&state->vcpis); + + list_for_each_entry(pos, &old_state->vcpis, next) { + /* Prune leftover freed VCPI allocations */ + if (!pos->vcpi) + continue; + + vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL); + if (!vcpi) + goto fail; + + drm_dp_mst_get_port_malloc(vcpi->port); + list_add(&vcpi->next, &state->vcpis); + } + return &state->base; + +fail: + list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) { + drm_dp_mst_put_port_malloc(pos->port); + kfree(pos); + } + kfree(state); + + return NULL; } static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, @@ -3131,14 +3682,99 @@ static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, { struct drm_dp_mst_topology_state *mst_state = to_dp_mst_topology_state(state); + struct drm_dp_vcpi_allocation *pos, *tmp; + + list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) { + /* We only keep references to ports with non-zero VCPIs */ + if (pos->vcpi) + drm_dp_mst_put_port_malloc(pos->port); + kfree(pos); + } kfree(mst_state); } -static const struct drm_private_state_funcs mst_state_funcs = { +static inline int +drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_topology_state *mst_state) +{ + struct drm_dp_vcpi_allocation *vcpi; + int avail_slots = 63, payload_count = 0; + + list_for_each_entry(vcpi, &mst_state->vcpis, next) { + /* Releasing VCPI is always OK-even if the port is gone */ + if (!vcpi->vcpi) { + DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n", + vcpi->port); + continue; + } + + DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n", + vcpi->port, vcpi->vcpi); + + avail_slots -= vcpi->vcpi; + if (avail_slots < 0) { + DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n", + vcpi->port, mst_state, + avail_slots + vcpi->vcpi); + return -ENOSPC; + } + + if (++payload_count > mgr->max_payloads) { + DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n", + mgr, mst_state, mgr->max_payloads); + return -EINVAL; + } + } + DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n", + mgr, mst_state, avail_slots, + 63 - avail_slots); + + return 0; +} + +/** + * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an + * atomic update is valid + * @state: Pointer to the new &struct drm_dp_mst_topology_state + * + * Checks the given topology state for an atomic update to ensure that it's + * valid. This includes checking whether there's enough bandwidth to support + * the new VCPI allocations in the atomic update. + * + * Any atomic drivers supporting DP MST must make sure to call this after + * checking the rest of their state in their + * &drm_mode_config_funcs.atomic_check() callback. + * + * See also: + * drm_dp_atomic_find_vcpi_slots() + * drm_dp_atomic_release_vcpi_slots() + * + * Returns: + * + * 0 if the new state is valid, negative error code otherwise. + */ +int drm_dp_mst_atomic_check(struct drm_atomic_state *state) +{ + struct drm_dp_mst_topology_mgr *mgr; + struct drm_dp_mst_topology_state *mst_state; + int i, ret = 0; + + for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { + ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state); + if (ret) + break; + } + + return ret; +} +EXPORT_SYMBOL(drm_dp_mst_atomic_check); + +const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = { .atomic_duplicate_state = drm_dp_mst_duplicate_state, .atomic_destroy_state = drm_dp_mst_destroy_state, }; +EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs); /** * drm_atomic_get_mst_topology_state: get MST topology state @@ -3216,13 +3852,11 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, return -ENOMEM; mst_state->mgr = mgr; + INIT_LIST_HEAD(&mst_state->vcpis); - /* max. time slots - one slot for MTP header */ - mst_state->avail_slots = 63; - - drm_atomic_private_obj_init(&mgr->base, + drm_atomic_private_obj_init(dev, &mgr->base, &mst_state->base, - &mst_state_funcs); + &drm_dp_mst_topology_state_funcs); return 0; } @@ -3234,6 +3868,7 @@ EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); */ void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) { + drm_dp_mst_topology_mgr_set_mst(mgr, false); flush_work(&mgr->work); flush_work(&mgr->destroy_connector_work); mutex_lock(&mgr->payload_lock); @@ -3249,6 +3884,23 @@ void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) } EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); +static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num) +{ + int i; + + if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS) + return false; + + for (i = 0; i < num - 1; i++) { + if (msgs[i].flags & I2C_M_RD || + msgs[i].len > 0xff) + return false; + } + + return msgs[num - 1].flags & I2C_M_RD && + msgs[num - 1].len <= 0xff; +} + /* I2C device */ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) @@ -3258,21 +3910,15 @@ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs struct drm_dp_mst_branch *mstb; struct drm_dp_mst_topology_mgr *mgr = port->mgr; unsigned int i; - bool reading = false; struct drm_dp_sideband_msg_req_body msg; struct drm_dp_sideband_msg_tx *txmsg = NULL; int ret; - mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); + mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); if (!mstb) return -EREMOTEIO; - /* construct i2c msg */ - /* see if last msg is a read */ - if (msgs[num - 1].flags & I2C_M_RD) - reading = true; - - if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) { + if (!remote_i2c_read_ok(msgs, num)) { DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n"); ret = -EIO; goto out; @@ -3286,6 +3932,7 @@ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; + msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP); } msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; @@ -3304,7 +3951,7 @@ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { - if (txmsg->reply.reply_type == 1) { /* got a NAK back */ + if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { ret = -EREMOTEIO; goto out; } @@ -3317,7 +3964,7 @@ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs } out: kfree(txmsg); - drm_dp_put_mst_branch_device(mstb); + drm_dp_mst_topology_put_mstb(mstb); return ret; } |