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e1000e: Fix link check race condition

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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: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Benjamin Poirier 2018-03-06 10:55:53 +09:00 committed by Jeff Kirsher
parent 3016e0a0c9
commit e2710dbf0d
2 changed files with 24 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
drivers/net/ethernet/intel/e1000e/ich8lan.c
View File

@ -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)

14
drivers/net/ethernet/intel/e1000e/mac.c
View File

@ -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;
}
/**