4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rui Sousa <rui.sousa@xxxxxxx> [ Upstream commit 01f8902bcf3ff124d0aeb88a774180ebcec20ace ] Fix hardware setup of multicast address hash: - Never clear the hardware hash (to avoid packet loss) - Construct the hash register values in software and then write once to hardware Signed-off-by: Rui Sousa <rui.sousa@xxxxxxx> Signed-off-by: Fugang Duan <fugang.duan@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/freescale/fec_main.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-) --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -2968,6 +2968,7 @@ static void set_multicast_list(struct ne struct netdev_hw_addr *ha; unsigned int i, bit, data, crc, tmp; unsigned char hash; + unsigned int hash_high = 0, hash_low = 0; if (ndev->flags & IFF_PROMISC) { tmp = readl(fep->hwp + FEC_R_CNTRL); @@ -2990,11 +2991,7 @@ static void set_multicast_list(struct ne return; } - /* Clear filter and add the addresses in hash register - */ - writel(0, fep->hwp + FEC_GRP_HASH_TABLE_HIGH); - writel(0, fep->hwp + FEC_GRP_HASH_TABLE_LOW); - + /* Add the addresses in hash register */ netdev_for_each_mc_addr(ha, ndev) { /* calculate crc32 value of mac address */ crc = 0xffffffff; @@ -3012,16 +3009,14 @@ static void set_multicast_list(struct ne */ hash = (crc >> (32 - HASH_BITS)) & 0x3f; - if (hash > 31) { - tmp = readl(fep->hwp + FEC_GRP_HASH_TABLE_HIGH); - tmp |= 1 << (hash - 32); - writel(tmp, fep->hwp + FEC_GRP_HASH_TABLE_HIGH); - } else { - tmp = readl(fep->hwp + FEC_GRP_HASH_TABLE_LOW); - tmp |= 1 << hash; - writel(tmp, fep->hwp + FEC_GRP_HASH_TABLE_LOW); - } + if (hash > 31) + hash_high |= 1 << (hash - 32); + else + hash_low |= 1 << hash; } + + writel(hash_high, fep->hwp + FEC_GRP_HASH_TABLE_HIGH); + writel(hash_low, fep->hwp + FEC_GRP_HASH_TABLE_LOW); } /* Set a MAC change in hardware. */