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/linux/drivers/net/ethernet/intel/e1000e/
H A Dmac.ce2710dbf0dc1e37d85368e2404049dadda848d5a Tue Mar 06 01:55:53 UTC 2018 Benjamin Poirier <bpoirier@suse.com> 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)
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>
H A Dich8lan.ce2710dbf0dc1e37d85368e2404049dadda848d5a Tue Mar 06 01:55:53 UTC 2018 Benjamin Poirier <bpoirier@suse.com> 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)
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>