From a043791f56147ab573ffcde7362edc01106dd639 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Sun, 11 Nov 2018 00:41:10 +0100 Subject: [PATCH] net: dsa: mv88e6xxx: Fix clearing of stats counters [ Upstream commit a9049ff9214da68df1179a7d5e36b43479abc9b8 ] The mv88e6161 would sometime fail to probe with a timeout waiting for the switch to complete an operation. This operation is supposed to clear the statistics counters. However, due to a read/modify/write, without the needed mask, the operation actually carried out was more random, with invalid parameters, resulting in the switch not responding. We need to preserve the histogram mode bits, so apply a mask to keep them. Reported-by: Chris Healy Fixes: 40cff8fca9e3 ("net: dsa: mv88e6xxx: Fix stats histogram mode") Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/dsa/mv88e6xxx/global1.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/dsa/mv88e6xxx/global1.c b/drivers/net/dsa/mv88e6xxx/global1.c index d721ccf..38e399e 100644 --- a/drivers/net/dsa/mv88e6xxx/global1.c +++ b/drivers/net/dsa/mv88e6xxx/global1.c @@ -567,6 +567,8 @@ int mv88e6xxx_g1_stats_clear(struct mv88e6xxx_chip *chip) if (err) return err; + /* Keep the histogram mode bits */ + val &= MV88E6XXX_G1_STATS_OP_HIST_RX_TX; val |= MV88E6XXX_G1_STATS_OP_BUSY | MV88E6XXX_G1_STATS_OP_FLUSH_ALL; err = mv88e6xxx_g1_write(chip, MV88E6XXX_G1_STATS_OP, val); -- 2.7.4