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| author | Thomas Gleixner <tglx@linutronix.de> | 2008-10-02 16:33:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-02 18:28:13 -0700 |
| commit | 717d438d1fde94decef874b9808379d1f4523453 (patch) | |
| tree | a0c2d71c2219e111668870f2692a92e3065d34fd /drivers | |
| parent | 4fa7553a075918e1e02a6039f9e826c8872b7049 (diff) | |
| download | linux-3.10-717d438d1fde94decef874b9808379d1f4523453.tar.gz linux-3.10-717d438d1fde94decef874b9808379d1f4523453.tar.bz2 linux-3.10-717d438d1fde94decef874b9808379d1f4523453.zip | |
e1000e: debug contention on NVM SWFLAG
This patch adds a mutex to the e1000e driver that would help
catch any collisions of two e1000e threads accessing hardware
at the same time.
description and patch updated by Jesse
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/e1000e/ich8lan.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c index f4b6744d71d..0b6095ba3ce 100644 --- a/drivers/net/e1000e/ich8lan.c +++ b/drivers/net/e1000e/ich8lan.c @@ -380,6 +380,9 @@ static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter) return 0; } +static DEFINE_MUTEX(nvm_mutex); +static pid_t nvm_owner = -1; + /** * e1000_acquire_swflag_ich8lan - Acquire software control flag * @hw: pointer to the HW structure @@ -393,6 +396,15 @@ static s32 e1000_acquire_swflag_ich8lan(struct e1000_hw *hw) u32 extcnf_ctrl; u32 timeout = PHY_CFG_TIMEOUT; + WARN_ON(preempt_count()); + + if (!mutex_trylock(&nvm_mutex)) { + WARN(1, KERN_ERR "e1000e mutex contention. Owned by pid %d\n", + nvm_owner); + mutex_lock(&nvm_mutex); + } + nvm_owner = current->pid; + while (timeout) { extcnf_ctrl = er32(EXTCNF_CTRL); extcnf_ctrl |= E1000_EXTCNF_CTRL_SWFLAG; @@ -407,6 +419,8 @@ static s32 e1000_acquire_swflag_ich8lan(struct e1000_hw *hw) if (!timeout) { hw_dbg(hw, "FW or HW has locked the resource for too long.\n"); + nvm_owner = -1; + mutex_unlock(&nvm_mutex); return -E1000_ERR_CONFIG; } @@ -428,6 +442,9 @@ static void e1000_release_swflag_ich8lan(struct e1000_hw *hw) extcnf_ctrl = er32(EXTCNF_CTRL); extcnf_ctrl &= ~E1000_EXTCNF_CTRL_SWFLAG; ew32(EXTCNF_CTRL, extcnf_ctrl); + + nvm_owner = -1; + mutex_unlock(&nvm_mutex); } /** |