> From: netdev-ow...@vger.kernel.org [mailto:netdev-
> ow...@vger.kernel.org] On Behalf Of Benjamin Poirier
> Sent: Monday, March 5, 2018 5:56 PM
> To: Kirsher, Jeffrey T
> Cc: Alexander Duyck ; Lennart Sorensen
> ; intel-wired-...@lists.osuosl.org;
> netdev@vger.kernel.org; linux-ker...@vger.kernel.org
> Subject: [PATCH 2/2] e1000e: Fix link check race condition
>
> 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 = 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
> Signed-off-by: Benjamin Poirier
> ---
> drivers/net/ethernet/intel/e1000e/ich8lan.c | 31 ---
> --
> drivers/net/ethernet/intel/e1000e/mac.c | 14 ++---
> 2 files changed, 24 insertions(+), 21 deletions(-)
Tested-by: Aaron Brown