This is a note to let you know that I've just added the patch titled igc: Handle already enabled taprio offload for basetime 0 to the 6.4-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-handle-already-enabled-taprio-offload-for-baseti.patch and it can be found in the queue-6.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5b7662266cd1b15b3162ed4f1c1bf7509118f885 Author: Florian Kauer <florian.kauer@xxxxxxxxxxxxx> Date: Wed Jun 14 16:07:11 2023 +0200 igc: Handle already enabled taprio offload for basetime 0 [ Upstream commit e5d88c53d03f8df864776431175d08c053645f50 ] Since commit e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv") it is possible to enable taprio offload with a basetime of 0. However, the check if taprio offload is already enabled (and thus -EALREADY should be returned for igc_save_qbv_schedule) still relied on adapter->base_time > 0. This can be reproduced as follows: # TAPRIO offload (flags == 0x2) and base-time = 0 sudo tc qdisc replace dev enp1s0 parent root handle 100 stab overhead 24 taprio \ num_tc 1 \ map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \ queues 1@0 \ base-time 0 \ sched-entry S 01 300000 \ flags 0x2 # The second call should fail with "Error: Device failed to setup taprio offload." # But that only happens if base-time was != 0 sudo tc qdisc replace dev enp1s0 parent root handle 100 stab overhead 24 taprio \ num_tc 1 \ map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \ queues 1@0 \ base-time 0 \ sched-entry S 01 300000 \ flags 0x2 Fixes: e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv") 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 f051ca733af1b..97eb3c390de9a 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -6127,7 +6127,7 @@ static int igc_save_qbv_schedule(struct igc_adapter *adapter, if (qopt->base_time < 0) return -ERANGE; - if (igc_is_device_id_i225(hw) && adapter->base_time) + if (igc_is_device_id_i225(hw) && adapter->taprio_offload_enable) return -EALREADY; if (!validate_schedule(adapter, qopt))