net: dsa: mv88e6xxx: Fix clearing of stats counters
authorAndrew Lunn <andrew@lunn.ch>
Sat, 10 Nov 2018 23:41:10 +0000 (00:41 +0100)
committerDavid S. Miller <davem@davemloft.net>
Sun, 11 Nov 2018 18:19:10 +0000 (10:19 -0800)
commita9049ff9214da68df1179a7d5e36b43479abc9b8
tree13032ddf45df812aeff628977c17d7b29b111e67
parent7ab412d33b4c7ff3e0148d3db25dd861edd1283d
net: dsa: mv88e6xxx: Fix clearing of stats counters

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 <Chris.Healy@zii.aero>
Fixes: 40cff8fca9e3 ("net: dsa: mv88e6xxx: Fix stats histogram mode")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/dsa/mv88e6xxx/global1.c