bnxt_en: Don't use rtnl lock to protect link change logic in workqueue.

Orabug: 27648355, 27648339

As a further improvement to the PF/VF link change logic, use a private
mutex instead of the rtnl lock to protect link change logic.  With the
new mutex, we don't have to take the rtnl lock in the workqueue when
we have to handle link related functions.  If the VF and PF drivers
are running on the same host and both take the rtnl lock and one is
waiting for the other, it will cause timeout.  This patch fixes these
timeouts.

Fixes: 90c694bb7181 ("bnxt_en: Fix RTNL lock usage on bnxt_update_link().")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit e2dc9b6e38fa3919e63d6d7905da70ca41cbf908)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index e81494379f0a9cd069cfc411c1cb9110365757f9..44cc17bb38962ac63d0691dc76c8d3542caae43b 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -6328,7 +6328,9 @@ static int __bnxt_open_nic(struct bnxt *bp, bool irq_re_init, bool link_re_init)
        }
 
        if (link_re_init) {
+               mutex_lock(&bp->link_lock);
                rc = bnxt_update_phy_setting(bp);
+               mutex_unlock(&bp->link_lock);
                if (rc)
                        netdev_warn(bp->dev, "failed to update phy settings\n");
        }
@@ -7008,30 +7010,28 @@ static void bnxt_sp_task(struct work_struct *work)
        if (test_and_clear_bit(BNXT_PERIODIC_STATS_SP_EVENT, &bp->sp_event))
                bnxt_hwrm_port_qstats(bp);
 
-       /* These functions below will clear BNXT_STATE_IN_SP_TASK.  They
-        * must be the last functions to be called before exiting.
-        */
        if (test_and_clear_bit(BNXT_LINK_CHNG_SP_EVENT, &bp->sp_event)) {
-               int rc = 0;
+               int rc;
 
+               mutex_lock(&bp->link_lock);
                if (test_and_clear_bit(BNXT_LINK_SPEED_CHNG_SP_EVENT,
                                       &bp->sp_event))
                        bnxt_hwrm_phy_qcaps(bp);
 
-               bnxt_rtnl_lock_sp(bp);
-               if (test_bit(BNXT_STATE_OPEN, &bp->state))
-                       rc = bnxt_update_link(bp, true);
-               bnxt_rtnl_unlock_sp(bp);
+               rc = bnxt_update_link(bp, true);
+               mutex_unlock(&bp->link_lock);
                if (rc)
                        netdev_err(bp->dev, "SP task can't update link (rc: %x)\n",
                                   rc);
        }
        if (test_and_clear_bit(BNXT_HWRM_PORT_MODULE_SP_EVENT, &bp->sp_event)) {
-               bnxt_rtnl_lock_sp(bp);
-               if (test_bit(BNXT_STATE_OPEN, &bp->state))
-                       bnxt_get_port_module_status(bp);
-               bnxt_rtnl_unlock_sp(bp);
+               mutex_lock(&bp->link_lock);
+               bnxt_get_port_module_status(bp);
+               mutex_unlock(&bp->link_lock);
        }
+       /* These functions below will clear BNXT_STATE_IN_SP_TASK.  They
+        * must be the last functions to be called before exiting.
+        */
        if (test_and_clear_bit(BNXT_RESET_TASK_SP_EVENT, &bp->sp_event))
                bnxt_reset(bp, false);
 
@@ -7701,6 +7701,7 @@ static int bnxt_probe_phy(struct bnxt *bp)
                           rc);
                return rc;
        }
+       mutex_init(&bp->link_lock);
 
        rc = bnxt_update_link(bp, false);
        if (rc) {

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 5f4adbe1648453107146712c83705cc7e86206ee..63711cfbb0b453f936beb5f1f2aa0b6153ece910 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1220,6 +1220,10 @@ struct bnxt {
        unsigned long           *ntp_fltr_bmap;
        int                     ntp_fltr_count;
 
+       /* To protect link related settings during link changes and
+        * ethtool settings changes.
+        */
+       struct mutex            link_lock;
        struct bnxt_link_info   link_info;
        struct ethtool_eee      eee;
        u32                     lpi_tmr_lo;

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 118b52081d52fac58a293477f0223a3e9d74020c..7b0ba4b9254cb3633b284d8cc98575f66b7c927b 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -1123,6 +1123,7 @@ static int bnxt_get_link_ksettings(struct net_device *dev,
        u32 ethtool_speed;
 
        ethtool_link_ksettings_zero_link_mode(lk_ksettings, supported);
+       mutex_lock(&bp->link_lock);
        bnxt_fw_to_ethtool_support_spds(link_info, lk_ksettings);
 
        ethtool_link_ksettings_zero_link_mode(lk_ksettings, advertising);
@@ -1170,6 +1171,7 @@ static int bnxt_get_link_ksettings(struct net_device *dev,
                        base->port = PORT_FIBRE;
        }
        base->phy_address = link_info->phy_addr;
+       mutex_unlock(&bp->link_lock);
 
        return 0;
 }
@@ -1328,6 +1330,7 @@ static int bnxt_set_link_ksettings(struct net_device *dev,
        if (!BNXT_SINGLE_PF(bp))
                return -EOPNOTSUPP;
 
+       mutex_lock(&bp->link_lock);
        if (base->autoneg == AUTONEG_ENABLE) {
                BNXT_ETHTOOL_TO_FW_SPDS(fw_advertising, lk_ksettings,
                                        advertising);
@@ -1372,6 +1375,7 @@ static int bnxt_set_link_ksettings(struct net_device *dev,
                rc = bnxt_hwrm_set_link_setting(bp, set_pause, false);
 
 set_setting_exit:
+       mutex_unlock(&bp->link_lock);
        return rc;
 }