]> git.baikalelectronics.ru Git - kernel.git/commit
net/mlx4_core: Avoid delays during VF driver device shutdown
authorJack Morgenstein <jackm@dev.mellanox.co.il>
Mon, 13 Mar 2017 17:29:08 +0000 (19:29 +0200)
committerDavid S. Miller <davem@davemloft.net>
Fri, 17 Mar 2017 03:14:51 +0000 (20:14 -0700)
commitfc19dbddf767ae849194c25ed65ca78740c7e0aa
treedc7aa5fa51bd213da221ad73f648c08e4e849235
parentea686499bf86c6f2c6810cf17a96359eac4e1012
net/mlx4_core: Avoid delays during VF driver device shutdown

Some Hypervisors detach VFs from VMs by instantly causing an FLR event
to be generated for a VF.

In the mlx4 case, this will cause that VF's comm channel to be disabled
before the VM has an opportunity to invoke the VF device's "shutdown"
method.

For such Hypervisors, there is a race condition between the VF's
shutdown method and its internal-error detection/reset thread.

The internal-error detection/reset thread (which runs every 5 seconds) also
detects a disabled comm channel. If the internal-error detection/reset
flow wins the race, we still get delays (while that flow tries repeatedly
to detect comm-channel recovery).

The cited commit fixed the command timeout problem when the
internal-error detection/reset flow loses the race.

This commit avoids the unneeded delays when the internal-error
detection/reset flow wins.

Fixes: 4c9a94bb77cc ("net/mlx4_core: Avoid command timeouts during VF driver device shutdown")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Reported-by: Simon Xiao <sixiao@microsoft.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/mellanox/mlx4/cmd.c
drivers/net/ethernet/mellanox/mlx4/main.c
include/linux/mlx4/device.h