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Commit 717d438d authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Linus Torvalds
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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: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4fa7553a

drivers/net/e1000e/ich8lan.c

+17 −0
Original line number Original line Diff line number Diff line
@@ -380,6 +380,9 @@ static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter) 
	return 0;

	return 0;

}

}





static DEFINE_MUTEX(nvm_mutex);

static pid_t nvm_owner = -1;



/**

/**

 *  e1000_acquire_swflag_ich8lan - Acquire software control flag

 *  e1000_acquire_swflag_ich8lan - Acquire software control flag

 *  @hw: pointer to the HW structure

 *  @hw: pointer to the HW structure
@@ -393,6 +396,15 @@ static s32 e1000_acquire_swflag_ich8lan(struct e1000_hw *hw) 
	u32 extcnf_ctrl;

	u32 extcnf_ctrl;

	u32 timeout = PHY_CFG_TIMEOUT;

	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) {

	while (timeout) {

		extcnf_ctrl = er32(EXTCNF_CTRL);

		extcnf_ctrl = er32(EXTCNF_CTRL);

		extcnf_ctrl |= E1000_EXTCNF_CTRL_SWFLAG;

		extcnf_ctrl |= E1000_EXTCNF_CTRL_SWFLAG;
@@ -407,6 +419,8 @@ static s32 e1000_acquire_swflag_ich8lan(struct e1000_hw *hw) 




	if (!timeout) {

	if (!timeout) {

		hw_dbg(hw, "FW or HW has locked the resource for too long.\n");

		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;

		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 = er32(EXTCNF_CTRL);

	extcnf_ctrl &= ~E1000_EXTCNF_CTRL_SWFLAG;

	extcnf_ctrl &= ~E1000_EXTCNF_CTRL_SWFLAG;

	ew32(EXTCNF_CTRL, extcnf_ctrl);

	ew32(EXTCNF_CTRL, extcnf_ctrl);



	nvm_owner = -1;

	mutex_unlock(&nvm_mutex);

}

}





/**

/**