Re: [Intel-gfx] [PATCH] drm/i915/guc: Fix flag query to not modify state

[Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>]

On 08/02/2022 02:07, John.C.Harrison@Intel.com wrote:
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> A flag query helper was actually writing to the flags word rather than
> just reading. Fix that. Also update the function's comment as it was
> out of date.
> 
> Fixes: 0f7976506de61 ("drm/i915/guc: Rework and simplify locking")
> Signed-off-by: John Harrison <john.c.harrison@intel.com>
> ---
>   drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 7 ++-----
>   1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> index b3a429a92c0d..d9f4218f5ef4 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -174,11 +174,8 @@ static inline void init_sched_state(struct intel_context *ce)
>   __maybe_unused
>   static bool sched_state_is_init(struct intel_context *ce)
>   {
> -	/*
> -	 * XXX: Kernel contexts can have SCHED_STATE_NO_LOCK_REGISTERED after
> -	 * suspend.
> -	 */
> -	return !(ce->guc_state.sched_state &=
> +	/* Kernel contexts can have SCHED_STATE_REGISTERED after suspend. */
> +	return !(ce->guc_state.sched_state &
>   		 ~(SCHED_STATE_BLOCKED_MASK | SCHED_STATE_REGISTERED));
>   }
>   

Looks important - what are the consequences?

Needs Cc: stable for 5.16?

Regards,

Tvrtko