net: qcom/emac: configure the external phy to allow pause frames

Pause frames are used to enable flow control.  A MAC can send and
receive pause frames in order to throttle traffic.  However, the PHY
must be configured to allow those frames to pass through.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/net/ethernet/qualcomm/emac/emac-mac.c b/drivers/net/ethernet/qualcomm/emac/emac-mac.c
index 6fb3bee904d3..70a55dcc431d 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac-mac.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac-mac.c
@@ -1003,6 +1003,12 @@ int emac_mac_up(struct emac_adapter *adpt)
         writel((u32)~DIS_INT, adpt->base + EMAC_INT_STATUS);
         writel(adpt->irq.mask, adpt->base + EMAC_INT_MASK);
 
+        /* Enable pause frames.  Without this feature, the EMAC has been shown
+         * to receive (and drop) frames with FCS errors at gigabit connections.
+         */
+        adpt->phydev->supported |= SUPPORTED_Pause | SUPPORTED_Asym_Pause;
+        adpt->phydev->advertising |= SUPPORTED_Pause | SUPPORTED_Asym_Pause;
+
         adpt->phydev->irq = PHY_IGNORE_INTERRUPT;
         phy_start(adpt->phydev);