net: stmmac: dwmac1000: provide multicast filter fallback

If we don't have a hardware multicast filter available then instead of
silently failing to listen for the requested ethernet broadcast
addresses fall back to receiving all multicast packets, in a similar
fashion to other drivers with no multicast filter.

Cc: stable@vger.kernel.org
Signed-off-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index efc6ec1..fc8759f 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -164,6 +164,9 @@ static void dwmac1000_set_filter(struct mac_device_info *hw,
                value = GMAC_FRAME_FILTER_PR | GMAC_FRAME_FILTER_PCF;
        } else if (dev->flags & IFF_ALLMULTI) {
                value = GMAC_FRAME_FILTER_PM;   /* pass all multi */
+       } else if (!netdev_mc_empty(dev) && (mcbitslog2 == 0)) {
+               /* Fall back to all multicast if we've no filter */
+               value = GMAC_FRAME_FILTER_PM;
        } else if (!netdev_mc_empty(dev)) {
                struct netdev_hw_addr *ha;