This is a note to let you know that I've just added the patch titled
igc: Fix launchtime before start of cycle
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
igc-fix-launchtime-before-start-of-cycle.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b12ced94910b133fa504dc2c81a9f876f1a96c84
Author: Florian Kauer <florian.kauer@xxxxxxxxxxxxx>
Date: Wed Jun 14 16:07:13 2023 +0200
igc: Fix launchtime before start of cycle
[ Upstream commit c1bca9ac0bcb355be11354c2e68bc7bf31f5ac5a ]
It is possible (verified on a running system) that frames are processed
by igc_tx_launchtime with a txtime before the start of the cycle
(baset_est).
However, the result of txtime - baset_est is written into a u32,
leading to a wrap around to a positive number. The following
launchtime > 0 check will only branch to executing launchtime = 0
if launchtime is already 0.
Fix it by using a s32 before checking launchtime > 0.
Fixes: db0b124f02ba ("igc: Enhance Qbv scheduling by using first flag bit")
Signed-off-by: Florian Kauer <florian.kauer@xxxxxxxxxxxxx>
Reviewed-by: Kurt Kanzenbach <kurt@xxxxxxxxxxxxx>
Tested-by: Naama Meir <naamax.meir@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index e5cbf867034e3..491b80407df49 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1013,7 +1013,7 @@ static __le32 igc_tx_launchtime(struct igc_ring *ring, ktime_t txtime,
ktime_t base_time = adapter->base_time;
ktime_t now = ktime_get_clocktai();
ktime_t baset_est, end_of_cycle;
- u32 launchtime;
+ s32 launchtime;
s64 n;
n = div64_s64(ktime_sub_ns(now, base_time), cycle_time);
