The check introduced in the commit a5fd39464a ("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: a5fd39464a ("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>
2b4cc3d3f4