Commit f9d5d17d authored Mar 01, 2022 by Sasha Neftin Committed by Greg Kroah-Hartman Apr 27, 2022

igc: Fix infinite loop in release_swfw_sync



[ Upstream commit 907862e9aef75bf89e2b265efcc58870be06081e ]

An infinite loop may occur if we fail to acquire the HW semaphore,
which is needed for resource release.
This will typically happen if the hardware is surprise-removed.
At this stage there is nothing to do, except log an error and quit.

Fixes: c0071c7a ("igc: Add HW initialization code")
Suggested-by: Dima Ruinskiy <dima.ruinskiy@intel.com>
Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 6d6271db

drivers/net/ethernet/intel/igc/igc_i225.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -156,8 +156,15 @@ void igc_release_swfw_sync_i225(struct igc_hw *hw, u16 mask)
		{
		u32 swfw_sync;

		while (igc_get_hw_semaphore_i225(hw))
		; /* Empty */
		/* Releasing the resource requires first getting the HW semaphore.
		* If we fail to get the semaphore, there is nothing we can do,
		* except log an error and quit. We are not allowed to hang here
		* indefinitely, as it may cause denial of service or system crash.
		*/
		if (igc_get_hw_semaphore_i225(hw)) {
		hw_dbg("Failed to release SW_FW_SYNC.\n");
		return;
		}

		swfw_sync = rd32(IGC_SW_FW_SYNC);
		swfw_sync &= ~mask;