diff options
| author | Benjamin Poirier <bpoirier@suse.com> | 2018-03-06 04:55:53 +0300 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2018-03-12 22:05:39 +0300 |
| commit | e2710dbf0dc1e37d85368e2404049dadda848d5a (patch) | |
| tree | f1b121b8473f89e4c6abfa94fe6e443f165a47f5 /drivers/net/ethernet/intel/e1000e/mac.c | |
| parent | 3016e0a0c91246e55418825ba9aae271be267522 (diff) | |
| download | linux-e2710dbf0dc1e37d85368e2404049dadda848d5a.tar.xz | |
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>
Diffstat (limited to 'drivers/net/ethernet/intel/e1000e/mac.c')
| -rw-r--r-- | drivers/net/ethernet/intel/e1000e/mac.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c index b322011ec282..5bdc3a2d4fd7 100644 --- a/drivers/net/ethernet/intel/e1000e/mac.c +++ b/drivers/net/ethernet/intel/e1000e/mac.c @@ -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; } /** |