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

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>

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 7906153c5c0556680e3788c82204fd8777a6790c..3f596de2abe3502b66cf8a05430fc25a123942f7 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -6345,7 +6345,9 @@ 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");
        }
@@ -7043,30 +7045,28 @@ 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);
 
@@ -7766,6 +7766,7 @@ 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 7b888d4b2b552a406b8157b3f037a299dc7645a4..d2925c04709a80109e1a20b846024b82858c71d0 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1290,6 +1290,10 @@ 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 8eff05a3e0e4b748c3a0d35661ce7b1901ddef61..b2cbc970b49754f1676a3880d2d8bfdaca051a9f 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -1052,6 +1052,7 @@ 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);
@@ -1099,6 +1100,7 @@ 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;
 }
@@ -1190,6 +1192,7 @@ 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);
@@ -1234,6 +1237,7 @@ 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;
 }