From: Andrew Lunn <andrew@lunn.ch>
Date: Thu, 4 Jun 2015 23:10:09 +0000 (+0200)
Subject: net: dsa: mv88e6xxx: Fix deadlock by double lock
X-Git-Tag: v4.2-rc1~130^2~123
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=80edb722b919500450e83c49c20a9dc706de2fa6;p=linux.git

net: dsa: mv88e6xxx: Fix deadlock by double lock

ethtool -S on a DSA interface can deadlock for some switches because
the same lock is taken twice. Use the register read function which
expects the lock to be already held.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Fixes: 31888234b736 ("net: dsa: mv88e6xxx: Replace stats mutex with SMI mutex")
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index 7fba330ce702..39530fa142b0 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -703,8 +703,8 @@ static void _mv88e6xxx_get_ethtool_stats(struct dsa_switch *ds,
 		u32 high = 0;
 
 		if (s->reg >= 0x100) {
-			ret = mv88e6xxx_reg_read(ds, REG_PORT(port),
-						 s->reg - 0x100);
+			ret = _mv88e6xxx_reg_read(ds, REG_PORT(port),
+						  s->reg - 0x100);
 			if (ret < 0)
 				goto error;
 			low = ret;