[igt-dev] [PATCH i-g-t 2/2] i915/i915_pm_rps: Write values in pm_rps_exit_handler only for min-max configs

[Kamil Konieczny]

On 2022-07-28 at 17:06:58 +0200, Karolina Drobnik wrote:
> From: Chris Wilson <chris at chris-wilson.co.uk>
> 
> pm_rps_exit_handler writes min and max frequencies to the corresponding
> sysfs files. In a situation where each test initializes only specific
> handlers, it's possible that the exit handler will dereference a NULL
> value in MIN and MAX file handlers.
> 
> To prevent this, check if the exit handler is called by a subtest
> that initialized handlers to files describing frequency constraints.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Karolina Drobnik <karolina.drobnik at intel.com>

Reviewed-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>

> ---
>  tests/i915/i915_pm_rps.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/tests/i915/i915_pm_rps.c b/tests/i915/i915_pm_rps.c
> index 0af46038..a45a6905 100644
> --- a/tests/i915/i915_pm_rps.c
> +++ b/tests/i915/i915_pm_rps.c
> @@ -859,12 +859,14 @@ static void engine_order(int i915)
> 
>  static void pm_rps_exit_handler(int sig)
>  {
> -	if (origfreqs[MIN] > readval(sysfs_files[MAX].filp)) {
> -		writeval(sysfs_files[MAX].filp, origfreqs[MAX]);
> -		writeval(sysfs_files[MIN].filp, origfreqs[MIN]);
> -	} else {
> -		writeval(sysfs_files[MIN].filp, origfreqs[MIN]);
> -		writeval(sysfs_files[MAX].filp, origfreqs[MAX]);
> +	if (sysfs_files[MAX].filp) {
> +		if (origfreqs[MIN] > readval(sysfs_files[MAX].filp)) {
> +			writeval(sysfs_files[MAX].filp, origfreqs[MAX]);
> +			writeval(sysfs_files[MIN].filp, origfreqs[MIN]);
> +		} else {
> +			writeval(sysfs_files[MIN].filp, origfreqs[MIN]);
> +			writeval(sysfs_files[MAX].filp, origfreqs[MAX]);
> +		}
>  	}
> 
>  	if (lh.igt_proc.running)
> --
> 2.25.1