sfc: Reset driver's MAC stats after MC reboot seen

If the MC reboots then the stats it reports to us will have been
reset.  We need to reset ours to get efx_update_diff_stat() working
properly.

(Ideally we would maintain stats across the reboot, but as this should
only happen immediately after a firmware upgrade it's not really worth
the trouble.)

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index e1967fbad161da9270c812c092eafd07ce9fa6c1..3ef71a0f99a8689a9a99006fa4053ad5aa23dc97 100644 (file)
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -207,7 +207,9 @@ out:
        return 0;
 }
 
-/* Test and clear MC-rebooted flag for this port/function */
+/* Test and clear MC-rebooted flag for this port/function; reset
+ * software state as necessary.
+ */
 int efx_mcdi_poll_reboot(struct efx_nic *efx)
 {
        unsigned int addr = FR_CZ_MC_TREG_SMEM + MCDI_STATUS(efx);
@@ -223,6 +225,11 @@ int efx_mcdi_poll_reboot(struct efx_nic *efx)
        if (value == 0)
                return 0;
 
+       /* MAC statistics have been cleared on the NIC; clear our copy
+        * so that efx_update_diff_stat() can continue to work.
+        */
+       memset(&efx->mac_stats, 0, sizeof(efx->mac_stats));
+
        EFX_ZERO_DWORD(reg);
        efx_writed(efx, &reg, addr);