[PATCH 4.14 177/228] net: stmmac: dwmac1000: provide multicast filter fallback

[Greg Kroah-Hartman]

From: Jonathan McDowell <noodles@xxxxxxxx>

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: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jonathan McDowell <noodles@xxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 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;