From e2269308359d5863b6aa1fcb95a425a2ab255f1f Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Thu, 14 Oct 2010 17:41:53 +0000 Subject: [PATCH] r6040: Fix multicast filter some more This code has been broken forever, but in several different and creative ways. So far as I can work out, the R6040 MAC filter has 4 exact-match entries, the first of which the driver uses for its assigned unicast address, plus a 64-entry hash-based filter for multicast addresses (maybe unicast as well?). The original version of this code would write the first 4 multicast addresses as exact-match entries from offset 1 (bug #1: there is no entry 4 so this could write to some PHY registers). It would fill the remainder of the exact-match entries with the broadcast address (bug #2: this would overwrite the last used entry). If more than 4 multicast addresses were configured, it would set up the hash table, write some random crap to the MAC control register (bug #3) and finally walk off the end of the list when filling the exact-match entries (bug #4). All of this seems to be pointless, since it sets the promiscuous bit when the interface is made promiscuous or if >4 multicast addresses are enabled, and never clears it (bug #5, masking bug #2). The recent(ish) changes to the multicast list fixed bug #4, but completely removed the limit on iteration over the exact-match entries (bug #6). Bug #4 was reported as and more recently as . Florian Fainelli attempted to fix these in commit 3bcf8229a8c49769e48d3e0bd1e20d8e003f8106, but that actually dealt with bugs #1-3, bug #4 having been fixed in mainline at that point. That commit fixes the most important current bug #6. Signed-off-by: Ben Hutchings Cc: stable@kernel.org [2.6.35 only] Signed-off-by: David S. Miller --- drivers/net/r6040.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/net/r6040.c b/drivers/net/r6040.c index 142c381e1d73..80666f097ce6 100644 --- a/drivers/net/r6040.c +++ b/drivers/net/r6040.c @@ -893,16 +893,18 @@ static void r6040_multicast_list(struct net_device *dev) /* Multicast Address 1~4 case */ i = 0; netdev_for_each_mc_addr(ha, dev) { - if (i < MCAST_MAX) { - adrp = (u16 *) ha->addr; - iowrite16(adrp[0], ioaddr + MID_1L + 8 * i); - iowrite16(adrp[1], ioaddr + MID_1M + 8 * i); - iowrite16(adrp[2], ioaddr + MID_1H + 8 * i); - } else { - iowrite16(0xffff, ioaddr + MID_1L + 8 * i); - iowrite16(0xffff, ioaddr + MID_1M + 8 * i); - iowrite16(0xffff, ioaddr + MID_1H + 8 * i); - } + if (i >= MCAST_MAX) + break; + adrp = (u16 *) ha->addr; + iowrite16(adrp[0], ioaddr + MID_1L + 8 * i); + iowrite16(adrp[1], ioaddr + MID_1M + 8 * i); + iowrite16(adrp[2], ioaddr + MID_1H + 8 * i); + i++; + } + while (i < MCAST_MAX) { + iowrite16(0xffff, ioaddr + MID_1L + 8 * i); + iowrite16(0xffff, ioaddr + MID_1M + 8 * i); + iowrite16(0xffff, ioaddr + MID_1H + 8 * i); i++; } } -- 2.20.1