tree 765d183a5a2bbbbcf58f5d364b10cf45b1ca6c4b
parent fa4059c5497e42fd9b91da1d32e14792f998e985
author Robert Hancock <hancock@sedsystems.ca> 1559925756 -0600
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1564125245 +0200

net: sfp: add mutex to prevent concurrent state checks

[ Upstream commit 2158e856f56bb762ef90f3ec244d41a519826f75 ]

sfp_check_state can potentially be called by both a threaded IRQ handler
and delayed work. If it is concurrently called, it could result in
incorrect state management. Add a st_mutex to protect the state - this
lock gets taken outside of code that checks and handle state changes, and
the existing sm_mutex nests inside of it.

Suggested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Robert Hancock <hancock@sedsystems.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>