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path: root/drivers/net/ethernet/qualcomm/emac
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-rw-r--r--drivers/net/ethernet/qualcomm/emac/emac-ethtool.c30
-rw-r--r--drivers/net/ethernet/qualcomm/emac/emac-mac.c22
-rw-r--r--drivers/net/ethernet/qualcomm/emac/emac.c3
-rw-r--r--drivers/net/ethernet/qualcomm/emac/emac.h3
4 files changed, 58 insertions, 0 deletions
diff --git a/drivers/net/ethernet/qualcomm/emac/emac-ethtool.c b/drivers/net/ethernet/qualcomm/emac/emac-ethtool.c
index bbe24639aa5a..c8c6231b87f3 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac-ethtool.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac-ethtool.c
@@ -88,6 +88,8 @@ static void emac_set_msglevel(struct net_device *netdev, u32 data)
static int emac_get_sset_count(struct net_device *netdev, int sset)
{
switch (sset) {
+ case ETH_SS_PRIV_FLAGS:
+ return 1;
case ETH_SS_STATS:
return EMAC_STATS_LEN;
default:
@@ -100,6 +102,10 @@ static void emac_get_strings(struct net_device *netdev, u32 stringset, u8 *data)
unsigned int i;
switch (stringset) {
+ case ETH_SS_PRIV_FLAGS:
+ strcpy(data, "single-pause-mode");
+ break;
+
case ETH_SS_STATS:
for (i = 0; i < EMAC_STATS_LEN; i++) {
strlcpy(data, emac_ethtool_stat_strings[i],
@@ -230,6 +236,27 @@ static int emac_get_regs_len(struct net_device *netdev)
return EMAC_MAX_REG_SIZE * sizeof(u32);
}
+#define EMAC_PRIV_ENABLE_SINGLE_PAUSE BIT(0)
+
+static int emac_set_priv_flags(struct net_device *netdev, u32 flags)
+{
+ struct emac_adapter *adpt = netdev_priv(netdev);
+
+ adpt->single_pause_mode = !!(flags & EMAC_PRIV_ENABLE_SINGLE_PAUSE);
+
+ if (netif_running(netdev))
+ return emac_reinit_locked(adpt);
+
+ return 0;
+}
+
+static u32 emac_get_priv_flags(struct net_device *netdev)
+{
+ struct emac_adapter *adpt = netdev_priv(netdev);
+
+ return adpt->single_pause_mode ? EMAC_PRIV_ENABLE_SINGLE_PAUSE : 0;
+}
+
static const struct ethtool_ops emac_ethtool_ops = {
.get_link_ksettings = phy_ethtool_get_link_ksettings,
.set_link_ksettings = phy_ethtool_set_link_ksettings,
@@ -253,6 +280,9 @@ static const struct ethtool_ops emac_ethtool_ops = {
.get_regs_len = emac_get_regs_len,
.get_regs = emac_get_regs,
+
+ .set_priv_flags = emac_set_priv_flags,
+ .get_priv_flags = emac_get_priv_flags,
};
void emac_set_ethtool_ops(struct net_device *netdev)
diff --git a/drivers/net/ethernet/qualcomm/emac/emac-mac.c b/drivers/net/ethernet/qualcomm/emac/emac-mac.c
index bcd4708b3745..0ea3ca09c689 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac-mac.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac-mac.c
@@ -551,6 +551,28 @@ static void emac_mac_start(struct emac_adapter *adpt)
mac &= ~(HUGEN | VLAN_STRIP | TPAUSE | SIMR | HUGE | MULTI_ALL |
DEBUG_MODE | SINGLE_PAUSE_MODE);
+ /* Enable single-pause-frame mode if requested.
+ *
+ * If enabled, the EMAC will send a single pause frame when the RX
+ * queue is full. This normally leads to packet loss because
+ * the pause frame disables the remote MAC only for 33ms (the quanta),
+ * and then the remote MAC continues sending packets even though
+ * the RX queue is still full.
+ *
+ * If disabled, the EMAC sends a pause frame every 31ms until the RX
+ * queue is no longer full. Normally, this is the preferred
+ * method of operation. However, when the system is hung (e.g.
+ * cores are halted), the EMAC interrupt handler is never called
+ * and so the RX queue fills up quickly and stays full. The resuling
+ * non-stop "flood" of pause frames sometimes has the effect of
+ * disabling nearby switches. In some cases, other nearby switches
+ * are also affected, shutting down the entire network.
+ *
+ * The user can enable or disable single-pause-frame mode
+ * via ethtool.
+ */
+ mac |= adpt->single_pause_mode ? SINGLE_PAUSE_MODE : 0;
+
writel_relaxed(csr1, adpt->csr + EMAC_EMAC_WRAPPER_CSR1);
writel_relaxed(mac, adpt->base + EMAC_MAC_CTRL);
diff --git a/drivers/net/ethernet/qualcomm/emac/emac.c b/drivers/net/ethernet/qualcomm/emac/emac.c
index 60850bfa3d32..759543512117 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac.c
@@ -443,6 +443,9 @@ static void emac_init_adapter(struct emac_adapter *adpt)
/* default to automatic flow control */
adpt->automatic = true;
+
+ /* Disable single-pause-frame mode by default */
+ adpt->single_pause_mode = false;
}
/* Get the clock */
diff --git a/drivers/net/ethernet/qualcomm/emac/emac.h b/drivers/net/ethernet/qualcomm/emac/emac.h
index 8ee4ec6aef2e..d7c9f44209d4 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac.h
+++ b/drivers/net/ethernet/qualcomm/emac/emac.h
@@ -363,6 +363,9 @@ struct emac_adapter {
bool tx_flow_control;
bool rx_flow_control;
+ /* True == use single-pause-frame mode. */
+ bool single_pause_mode;
+
/* Ring parameter */
u8 tpd_burst;
u8 rfd_burst;