Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit da2b4ae7 authored by Benjamin Poirier's avatar Benjamin Poirier Committed by Greg Kroah-Hartman
Browse files

e1000e: Fix link check race condition 

commit e2710dbf0dc1e37d85368e2404049dadda848d5a upstream.

Alex reported the following race condition:

/* link goes up... interrupt... schedule watchdog */
\ e1000_watchdog_task
	\ e1000e_has_link
		\ hw->mac.ops.check_for_link() === e1000e_check_for_copper_link
			\ e1000e_phy_has_link_generic(..., &link)
				link = true

					 /* link goes down... interrupt */
					 \ e1000_msix_other
						 hw->mac.get_link_status = true

			/* link is up */
			mac->get_link_status = false

		link_active = true
		/* link_active is true, wrongly, and stays so because
		 * get_link_status is false */

Avoid this problem by making sure that we don't set get_link_status = false
after having checked the link.

It seems this problem has been present since the introduction of e1000e.

Link: https://lkml.org/lkml/2018/1/29/338


Reported-by: default avatarAlexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: default avatarBenjamin Poirier <bpoirier@suse.com>
Acked-by: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dc2aa33a

drivers/net/ethernet/intel/e1000e/ich8lan.c

+17 −14
Original line number Diff line number Diff line
@@ -1383,6 +1383,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
	 */

	if (!mac->get_link_status)

		return 0;

	mac->get_link_status = false;



	/* First we want to see if the MII Status Register reports

	 * link.  If so, then we want to get the current speed/duplex
@@ -1390,12 +1391,12 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
	 */

	ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);

	if (ret_val)

		return ret_val;

		goto out;



	if (hw->mac.type == e1000_pchlan) {

		ret_val = e1000_k1_gig_workaround_hv(hw, link);

		if (ret_val)

			return ret_val;

			goto out;

	}



	/* When connected at 10Mbps half-duplex, some parts are excessively
@@ -1428,7 +1429,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 


		ret_val = hw->phy.ops.acquire(hw);

		if (ret_val)

			return ret_val;

			goto out;



		if (hw->mac.type == e1000_pch2lan)

			emi_addr = I82579_RX_CONFIG;
@@ -1450,7 +1451,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
		hw->phy.ops.release(hw);



		if (ret_val)

			return ret_val;

			goto out;



		if (hw->mac.type >= e1000_pch_spt) {

			u16 data;
@@ -1459,14 +1460,14 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
			if (speed == SPEED_1000) {

				ret_val = hw->phy.ops.acquire(hw);

				if (ret_val)

					return ret_val;

					goto out;



				ret_val = e1e_rphy_locked(hw,

							  PHY_REG(776, 20),

							  &data);

				if (ret_val) {

					hw->phy.ops.release(hw);

					return ret_val;

					goto out;

				}



				ptr_gap = (data & (0x3FF << 2)) >> 2;
@@ -1480,18 +1481,18 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
				}

				hw->phy.ops.release(hw);

				if (ret_val)

					return ret_val;

					goto out;

			} else {

				ret_val = hw->phy.ops.acquire(hw);

				if (ret_val)

					return ret_val;

					goto out;



				ret_val = e1e_wphy_locked(hw,

							  PHY_REG(776, 20),

							  0xC023);

				hw->phy.ops.release(hw);

				if (ret_val)

					return ret_val;

					goto out;



			}

		}
@@ -1518,7 +1519,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
	    (hw->adapter->pdev->device == E1000_DEV_ID_PCH_I218_V3)) {

		ret_val = e1000_k1_workaround_lpt_lp(hw, link);

		if (ret_val)

			return ret_val;

			goto out;

	}

	if (hw->mac.type >= e1000_pch_lpt) {

		/* Set platform power management values for
@@ -1526,7 +1527,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
		 */

		ret_val = e1000_platform_pm_pch_lpt(hw, link);

		if (ret_val)

			return ret_val;

			goto out;

	}



	/* Clear link partner's EEE ability */
@@ -1549,9 +1550,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
	}



	if (!link)

		return 0;	/* No link detected */



	mac->get_link_status = false;

		goto out;



	switch (hw->mac.type) {

	case e1000_pch2lan:
@@ -1617,6 +1616,10 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw) 
		e_dbg("Error configuring flow control\n");



	return ret_val;



out:

	mac->get_link_status = true;

	return ret_val;

}



static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)

drivers/net/ethernet/intel/e1000e/mac.c

+7 −7
Original line number Diff line number Diff line
@@ -424,19 +424,15 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) 
	 */

	if (!mac->get_link_status)

		return 0;

	mac->get_link_status = false;



	/* First we want to see if the MII Status Register reports

	 * link.  If so, then we want to get the current speed/duplex

	 * of the PHY.

	 */

	ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);

	if (ret_val)

		return ret_val;



	if (!link)

		return 0;	/* No link detected */



	mac->get_link_status = false;

	if (ret_val || !link)

		goto out;



	/* Check if there was DownShift, must be checked

	 * immediately after link-up
@@ -465,6 +461,10 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) 
		e_dbg("Error configuring flow control\n");



	return ret_val;



out:

	mac->get_link_status = true;

	return ret_val;

}



/**