diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 18 | ||||
| -rw-r--r-- | drivers/base/core.c | 27 | ||||
| -rw-r--r-- | include/linux/fwnode.h | 2 |
3 files changed, 46 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index dbc22d684627..29985152b66d 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1350,6 +1350,24 @@ can be changed at run time by the max_graph_depth file in the tracefs tracing directory. default: 0 (no limit) + fw_devlink= [KNL] Create device links between consumer and supplier + devices by scanning the firmware to infer the + consumer/supplier relationships. This feature is + especially useful when drivers are loaded as modules as + it ensures proper ordering of tasks like device probing + (suppliers first, then consumers), supplier boot state + clean up (only after all consumers have probed), + suspend/resume & runtime PM (consumers first, then + suppliers). + Format: { off | permissive | on | rpm } + off -- Don't create device links from firmware info. + permissive -- Create device links from firmware info + but use it only for ordering boot state clean + up (sync_state() calls). + on -- Create device links from firmware info and use it + to enforce probe and suspend/resume ordering. + rpm -- Like "on", but also use to order runtime PM. + gamecon.map[2|3]= [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port) diff --git a/drivers/base/core.c b/drivers/base/core.c index 79863354c801..922680af9051 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2332,6 +2332,31 @@ static int device_private_init(struct device *dev) return 0; } +u32 fw_devlink_flags; +static int __init fw_devlink_setup(char *arg) +{ + if (!arg) + return -EINVAL; + + if (strcmp(arg, "off") == 0) { + fw_devlink_flags = 0; + } else if (strcmp(arg, "permissive") == 0) { + fw_devlink_flags = DL_FLAG_SYNC_STATE_ONLY; + } else if (strcmp(arg, "on") == 0) { + fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER; + } else if (strcmp(arg, "rpm") == 0) { + fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER | + DL_FLAG_PM_RUNTIME; + } + return 0; +} +early_param("fw_devlink", fw_devlink_setup); + +u32 fw_devlink_get_flags(void) +{ + return fw_devlink_flags; +} + /** * device_add - add device to device hierarchy. * @dev: device. @@ -2480,7 +2505,7 @@ int device_add(struct device *dev) */ device_link_add_missing_supplier_links(); - if (fwnode_has_op(dev->fwnode, add_links)) { + if (fw_devlink_flags && fwnode_has_op(dev->fwnode, add_links)) { fw_ret = fwnode_call_int_op(dev->fwnode, add_links, dev); if (fw_ret == -ENODEV) device_link_wait_for_mandatory_supplier(dev); diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h index 8feeb94b8acc..e0abafbb17f8 100644 --- a/include/linux/fwnode.h +++ b/include/linux/fwnode.h @@ -170,4 +170,6 @@ struct fwnode_operations { } while (false) #define get_dev_from_fwnode(fwnode) get_device((fwnode)->dev) +extern u32 fw_devlink_get_flags(void); + #endif |