[PATCH 5.7 052/204] net: stmmac: dwmac1000: provide multicast filter fallback

Greg Kroah-Hartman
2020-08-20T09:37:16Z

From: Jonathan McDowell <noodles@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: stable@vger.kernel.org
Signed-off-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@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
@@ -164,6 +164,9 @@ static void dwmac1000_set_filter(struct
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;