Re: [Intel-wired-lan] [PATCH net v2 3/6] igc: Handle already enabled taprio offload for basetime 0

[naamax.meir]

On 6/19/2023 13:08, Florian Kauer wrote:
> 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 for i225
> (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>
> ---
>   drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Tested-by: Naama Meir <naamax.meir@xxxxxxxxxxxxxxx>