Re: [PATCH v19 03/11] perf: arm_pmuv3: Don't disable counter in armv8pmu_enable_event()

From: Anshuman Khandual
Date: Mon Feb 03 2025 - 01:38:53 EST


On 2/3/25 06:12, Rob Herring (Arm) wrote:
> From: Mark Rutland <mark.rutland@xxxxxxx>
>
> Currently armv8pmu_enable_event() starts by disabling the event counter
> it has been asked to enable. This should not be necessary as the counter
> (and the PMU as a whole) should not be active when
> armv8pmu_enable_event() is called.
Makes sense.

>
> Remove the redundant call to armv8pmu_disable_event_counter(). At the
> same time, remove the comment immeditately above as everything it says

s/immeditately/immediately

> is obvious from the function names below.

But should this comment drop change be folded into the next patch which
exclusively drops all obviously redundant disable/enable comments.

>
> Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
> Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
> ---
> drivers/perf/arm_pmuv3.c | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c
> index 9ebc950559c0..5406b9ca591a 100644
> --- a/drivers/perf/arm_pmuv3.c
> +++ b/drivers/perf/arm_pmuv3.c
> @@ -795,11 +795,6 @@ static void armv8pmu_enable_user_access(struct arm_pmu *cpu_pmu)
>
> static void armv8pmu_enable_event(struct perf_event *event)
> {
> - /*
> - * Enable counter and interrupt, and set the counter to count
> - * the event that we're interested in.
> - */
> - armv8pmu_disable_event_counter(event);
> armv8pmu_write_event_type(event);
> armv8pmu_enable_event_irq(event);
> armv8pmu_enable_event_counter(event);
>

Otherwise LGTM.

Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>