From: Florian Fainelli Date: Sun, 18 Mar 2018 18:23:05 +0000 (-0700) Subject: net: dsa: mv88e6xxx: Fix missing register lock in serdes_get_stats X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=ef44d78d8937146269ec3f0de966817a6d630d5e;p=openwrt%2Fstaging%2Fblogic.git net: dsa: mv88e6xxx: Fix missing register lock in serdes_get_stats We can hit the register lock not held assertion with the following path: [ 34.170631] mv88e6085 0.1:00: Switch registers lock not held! [ 34.176510] CPU: 0 PID: 950 Comm: ethtool Not tainted 4.16.0-rc4 #143 [ 34.182985] Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree) [ 34.189519] Backtrace: [ 34.192033] [<8010c4b4>] (dump_backtrace) from [<8010c788>] (show_stack+0x20/0x24) [ 34.199680] r6:9f5dc010 r5:00000011 r4:9f5dc010 r3:00000000 [ 34.205434] [<8010c768>] (show_stack) from [<80679d38>] (dump_stack+0x24/0x28) [ 34.212719] [<80679d14>] (dump_stack) from [<804844a8>] (mv88e6xxx_read+0x70/0x7c) [ 34.220376] [<80484438>] (mv88e6xxx_read) from [<804870dc>] (mv88e6xxx_port_get_cmode+0x34/0x4c) [ 34.229257] r5:a09cd128 r4:9ee31d07 [ 34.232880] [<804870a8>] (mv88e6xxx_port_get_cmode) from [<80487e6c>] (mv88e6352_port_has_serdes+0x24/0x64) [ 34.242690] r4:9f5dc010 [ 34.245309] [<80487e48>] (mv88e6352_port_has_serdes) from [<804880b8>] (mv88e6352_serdes_get_stats+0x28/0x12c) [ 34.255389] r4:00000001 [ 34.257973] [<80488090>] (mv88e6352_serdes_get_stats) from [<804811e8>] (mv88e6xxx_get_ethtool_stats+0xb0/0xc0) [ 34.268156] r10:00000000 r9:00000000 r8:00000000 r7:a09cd020 r6:00000001 r5:9f5dc01c [ 34.276052] r4:9f5dc010 [ 34.278631] [<80481138>] (mv88e6xxx_get_ethtool_stats) from [<8064f740>] (dsa_slave_get_ethtool_stats+0xbc/0xc4) mv88e6xxx_get_ethtool_stats() calls mv88e6xxx_get_stats() which calls both chip->info->ops->stats_get_stats(), which holds the register lock, and chip->info->ops->serdes_get_stats() which does not. Have chip->info->ops->serdes_get_stats() be running with the register lock held to avoid such assertions. Fixes: 436fe17d273b ("net: dsa: mv88e6xxx: Allow the SERDES interfaces to have statistics") Signed-off-by: Florian Fainelli Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index 41f872d4ba3c..d21f6c93c0c2 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -849,7 +849,9 @@ static void mv88e6xxx_get_stats(struct mv88e6xxx_chip *chip, int port, if (chip->info->ops->serdes_get_stats) { data += count; + mutex_lock(&chip->reg_lock); chip->info->ops->serdes_get_stats(chip, port, data); + mutex_unlock(&chip->reg_lock); } }