netdev - [4/5][BNX2]: Fix occasional counter corruption on 5708.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 04 Jun 2007 17:01:08 -0700
From:	"Michael Chan" <mchan@...adcom.com>
To:	davem@...emloft.net
cc:	andy@...yhouse.net, netdev@...r.kernel.org, jd@...junkt.com,
	cat@....com.au
Subject: [4/5][BNX2]: Fix occasional counter corruption on 5708.

[BNX2]: Fix occasional counter corruption on 5708.

The statistics block DMA on 5708 can be messed up occasionally on the
average of about once per hour.  If the user is reading the counters
within one second after the corruption, the counters will be all
messed up.  One second later, the counters will be ok again until the
next corruption occurs.

The workaround is to disable the periodic statistics DMA.  Instead,
we manually trigger the DMA once a second in bnx2_timer().  This
manual trigger of the DMA avoids the problem.

As a consequence, we can only allow 0 or 1 second settings for
ethtool -C statistics block.

Thanks to Jean-Daniel Pauget <jd@...junkt.com> and
CaT <cat@....com.au> for reporting this rare problem.

Signed-off-by: Michael Chan <mchan@...adcom.com>

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index c03282c..5654cc7 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -3783,7 +3783,10 @@ bnx2_init_chip(struct bnx2 *bp)
 	REG_WR(bp, BNX2_HC_CMD_TICKS,
 	       (bp->cmd_ticks_int << 16) | bp->cmd_ticks);
 
-	REG_WR(bp, BNX2_HC_STATS_TICKS, bp->stats_ticks & 0xffff00);
+	if (CHIP_NUM(bp) == CHIP_NUM_5708)
+		REG_WR(bp, BNX2_HC_STATS_TICKS, 0);
+	else
+		REG_WR(bp, BNX2_HC_STATS_TICKS, bp->stats_ticks & 0xffff00);
 	REG_WR(bp, BNX2_HC_STAT_COLLECT_TICKS, 0xbb8);  /* 3ms */
 
 	if (CHIP_ID(bp) == CHIP_ID_5706_A1)
@@ -4636,6 +4639,11 @@ bnx2_timer(unsigned long data)
 
 	bp->stats_blk->stat_FwRxDrop = REG_RD_IND(bp, BNX2_FW_RX_DROP_COUNT);
 
+	/* workaround occasional corrupted counters */
+	if (CHIP_NUM(bp) == CHIP_NUM_5708 && bp->stats_ticks)
+		REG_WR(bp, BNX2_HC_COMMAND, bp->hc_cmd |
+					    BNX2_HC_COMMAND_STATS_NOW);
+
 	if (bp->phy_flags & PHY_SERDES_FLAG) {
 		if (CHIP_NUM(bp) == CHIP_NUM_5706)
 			bnx2_5706_serdes_timer(bp);
@@ -5446,6 +5454,10 @@ bnx2_set_coalesce(struct net_device *dev, struct ethtool_coalesce *coal)
 		0xff;
 
 	bp->stats_ticks = coal->stats_block_coalesce_usecs;
+	if (CHIP_NUM(bp) == CHIP_NUM_5708) {
+		if (bp->stats_ticks != 0 && bp->stats_ticks != USEC_PER_SEC)
+			bp->stats_ticks = USEC_PER_SEC;
+	}
 	if (bp->stats_ticks > 0xffff00) bp->stats_ticks = 0xffff00;
 	bp->stats_ticks &= 0xffff00;
 


-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html