[PATCH 4.19 26/92] net: stmmac: dwmac1000: provide multicast filter fallback

[Greg Kroah-Hartman]

From: Jonathan McDowell <nood...@earth.li>

commit 592d751c1e174df5ff219946908b005eb48934b3 upstream.

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: sta...@vger.kernel.org
Signed-off-by: Jonathan McDowell <nood...@earth.li>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -176,6 +176,9 @@ static void dwmac1000_set_filter(struct
                value = GMAC_FRAME_FILTER_PR;
        } 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;