diff mbox series

[net,v2,5/6] igc: Fix launchtime before start of cycle

Message ID 20230619100858.116286-6-florian.kauer@linutronix.de
State New
Headers
Series igc: Fix corner cases for TSN offload |

Commit Message

Florian Kauer June 19, 2023, 10:08 a.m. UTC 
  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@linutronix.de>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

naamax.meir July 5, 2023, 11:06 a.m. UTC | #1 
On 6/19/2023 13:08, Florian Kauer wrote:
> 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@linutronix.de>
> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
> ---
>   drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)


Tested-by: Naama Meir <naamax.meir@linux.intel.com>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 9c04df900b59..565c72bd737d 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1017,7 +1017,7 @@  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);