AKASHI Takahiro 2b4cc3d3f4 igc: fix the validation logic for taprio's gate list
The check introduced in the commit a5fd39464a40 ("igc: Lift TAPRIO schedule
restriction") can detect a false positive error in some corner case.
For instance,
    tc qdisc replace ... taprio num_tc 4
	...
	sched-entry S 0x01 100000	# slot#1
	sched-entry S 0x03 100000	# slot#2
	sched-entry S 0x04 100000	# slot#3
	sched-entry S 0x08 200000	# slot#4
	flags 0x02			# hardware offload

Here the queue#0 (the first queue) is on at the slot#1 and #2,
and off at the slot#3 and #4. Under the current logic, when the slot#4
is examined, validate_schedule() returns *false* since the enablement
count for the queue#0 is two and it is already off at the previous slot
(i.e. #3). But this definition is truely correct.

Let's fix the logic to enforce a strict validation for consecutively-opened
slots.

Fixes: a5fd39464a40 ("igc: Lift TAPRIO schedule restriction")
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
2023-03-16 09:06:56 -07:00
..
2021-05-26 09:11:41 -07:00
2022-07-18 09:34:38 -07:00
2020-06-29 18:21:09 -07:00
2020-05-19 15:01:48 -07:00
2022-11-02 11:38:22 -07:00
2023-02-02 20:48:23 -08:00
2021-05-20 10:21:42 -07:00
2022-12-15 13:19:49 -08:00
2021-03-29 09:09:53 -07:00