sfc: Replace stats_enabled flag with a disable count

Currently we use a spin-lock to serialise statistics fetches and also
to inhibit them for short periods of time, plus a flag to
enable/disable statistics fetches for longer periods of time, during
online reset.  This was apparently insufficient to deal with the several
reasons for stats being disabled.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 1 deletions

diff --git a/drivers/net/sfc/sfe4001.c b/drivers/net/sfc/sfe4001.c
index 853057e87fb2..cb25ae5b257a 100644
--- a/drivers/net/sfc/sfe4001.c
+++ b/drivers/net/sfc/sfe4001.c
@@ -235,12 +235,18 @@ static ssize_t set_phy_flash_cfg(struct device *dev,
         } else if (efx->state != STATE_RUNNING || netif_running(efx->net_dev)) {
                 err = -EBUSY;
         } else {
+                /* Reset the PHY, reconfigure the MAC and enable/disable
+                 * MAC stats accordingly. */
                 efx->phy_mode = new_mode;
+                if (new_mode & PHY_MODE_SPECIAL)
+                        efx_stats_disable(efx);
                 if (efx->board_info.type == EFX_BOARD_SFE4001)
                         err = sfe4001_poweron(efx);
                 else
                         err = sfn4111t_reset(efx);
                 efx_reconfigure_port(efx);
+                if (!(new_mode & PHY_MODE_SPECIAL))
+                        efx_stats_enable(efx);
         }
         rtnl_unlock();
 
@@ -329,6 +335,11 @@ int sfe4001_init(struct efx_nic *efx)
         efx->board_info.monitor = sfe4001_check_hw;
         efx->board_info.fini = sfe4001_fini;
 
+        if (efx->phy_mode & PHY_MODE_SPECIAL) {
+                /* PHY won't generate a 156.25 MHz clock and MAC stats fetch
+                 * will fail. */
+                efx_stats_disable(efx);
+        }
         rc = sfe4001_poweron(efx);
         if (rc)
                 goto fail_ioexp;
@@ -405,8 +416,10 @@ int sfn4111t_init(struct efx_nic *efx)
         if (rc)
                 goto fail_hwmon;
 
-        if (efx->phy_mode & PHY_MODE_SPECIAL)
+        if (efx->phy_mode & PHY_MODE_SPECIAL) {
+                efx_stats_disable(efx);
                 sfn4111t_reset(efx);
+        }
 
         return 0;