i40e: Error handling for link event

There exists an intermittent bug which causes the 'Link Detected'
field reported by the 'ethtool <iface>' command to be 'Yes' when
in fact, there is no link. This patch fixes the problem by
enabling temporary link polling when i40e_get_link_status returns
an error. This causes the driver to remember that an admin queue
command failed and polls, until the function returns with a success.

Change-Id: I64c69b008db4017b8729f3fc27b8f65c8fe2eaa0
Signed-off-by: Harshitha Ramamurthy <harshitha.ramamurthy@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index f4c4ee3..82d8040 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -349,6 +349,7 @@ struct i40e_pf {
 #define I40E_FLAG_HAVE_CRT_RETIMER             BIT_ULL(52)
 #define I40E_FLAG_PTP_L4_CAPABLE               BIT_ULL(53)
 #define I40E_FLAG_WOL_MC_MAGIC_PKT_WAKE                BIT_ULL(54)
+#define I40E_FLAG_TEMP_LINK_POLLING            BIT_ULL(55)
 
        /* tracks features that get auto disabled by errors */
        u64 auto_disable_flags;

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index df78271..199ef34 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -6353,7 +6353,16 @@ static void i40e_link_event(struct i40e_pf *pf)
        old_link = (pf->hw.phy.link_info_old.link_info & I40E_AQ_LINK_UP);
 
        status = i40e_get_link_status(&pf->hw, &new_link);
-       if (status) {
+
+       /* On success, disable temp link polling */
+       if (status == I40E_SUCCESS) {
+               if (pf->flags & I40E_FLAG_TEMP_LINK_POLLING)
+                       pf->flags &= ~I40E_FLAG_TEMP_LINK_POLLING;
+       } else {
+               /* Enable link polling temporarily until i40e_get_link_status
+                * returns I40E_SUCCESS
+                */
+               pf->flags |= I40E_FLAG_TEMP_LINK_POLLING;
                dev_dbg(&pf->pdev->dev, "couldn't get link state, status: %d\n",
                        status);
                return;
@@ -6405,7 +6414,8 @@ static void i40e_watchdog_subtask(struct i40e_pf *pf)
                return;
        pf->service_timer_previous = jiffies;
 
-       if (pf->flags & I40E_FLAG_LINK_POLLING_ENABLED)
+       if ((pf->flags & I40E_FLAG_LINK_POLLING_ENABLED) ||
+           (pf->flags & I40E_FLAG_TEMP_LINK_POLLING))
                i40e_link_event(pf);
 
        /* Update the stats for active netdevs so the network stack