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authorThomas Gleixner <tglx@linutronix.de>2008-10-02 16:33:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-02 18:28:13 -0700
commit717d438d1fde94decef874b9808379d1f4523453 (patch)
treea0c2d71c2219e111668870f2692a92e3065d34fd
parent4fa7553a075918e1e02a6039f9e826c8872b7049 (diff)
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>
-rw-r--r--drivers/net/e1000e/ich8lan.c17
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);
}
/**