From 989508ba60da6dce79f8aaee1be6c092fd4c67f8 Mon Sep 17 00:00:00 2001 From: Srinivas Kandagatla Date: Wed, 16 Nov 2011 21:58:01 +0000 Subject: [PATCH] stmmac: remove spin_lock in stmmac_ioctl. This patch removes un-needed spin_lock in stmmac_ioctl while reading and writing mdio registers. While holding spin_lock the code must be atomic, which is not true in this case as both mdiobus_read and writes have mutex locks. Without this patch reading mdio registers via mii-tool results in below BUG: mii-tool -vvv eth0" Using SIOCGMIIPHY=0x8947 BUG: sleeping function called from invalid context at kernel/mutex.c:287 in_atomic(): 1, irqs_disabled(): 0, pid: 614, name: mii-tool 2 locks held by mii-tool/614: #0: (rtnl_mutex){......}, at: [] dev_ioctl+0x550/0x674 #1: (&priv->lock){......}, at: [] stmmac_ioctl+0x4c/0x78 [] (unwind_backtrace+0x0/0xcc) from [] (mutex_lock_nested+0x24/0x35c) [] (mutex_lock_nested+0x24/0x35c) from [] (mdiobus_read+0x44/0x70) [] (mdiobus_read+0x44/0x70) from [] (phy_mii_ioctl+0x4c/0x138) [] (phy_mii_ioctl+0x4c/0x138) from [] (stmmac_ioctl+0x5c/0x78) [] (stmmac_ioctl+0x5c/0x78) from [] (dev_ifsioc+0x2a4/0x2c8) [] (dev_ifsioc+0x2a4/0x2c8) from [] (dev_ioctl+0x560/0x674) [] (dev_ioctl+0x560/0x674) from [] (vfs_ioctl+0x2c/0x8c) [] (vfs_ioctl+0x2c/0x8c) from [] (do_vfs_ioctl+0x530/0x578) [] (do_vfs_ioctl+0x530/0x578) from [] (sys_ioctl+0x34/0x54) [] (sys_ioctl+0x34/0x54) from [] (ret_fast_syscall+0x0/0x2c) Signed-off-by: Srinivas Kandagatla Signed-off-by: Giuseppe Cavallaro Signed-off-by: David S. Miller --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 7f3ffd3742d8..29dd87c675dc 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1536,9 +1536,7 @@ static int stmmac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) if (!priv->phydev) return -EINVAL; - spin_lock(&priv->lock); ret = phy_mii_ioctl(priv->phydev, rq, cmd); - spin_unlock(&priv->lock); return ret; } -- GitLab