[Intel-gfx] [PATCH] drm/i915: intel_engine_init_global_seqno() requires atomic kmap

[Tvrtko Ursulin]

On 20/03/2017 14:56, Chris Wilson wrote:
> As intel_engine_init_global_seqno() may be called by
> nop_submit_request() from inside irq context, we have to use atomic
> versions of kmap/kunmap. This is rare as this requires using gen8 legacy
> ringbuffer submission.
>
> Reported-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_engine_cs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
> index 4200faa520c7..ef3c62000697 100644
> --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> @@ -242,12 +242,12 @@ void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno)
>  		void *semaphores;
>
>  		/* Semaphores are in noncoherent memory, flush to be safe */
> -		semaphores = kmap(page);
> +		semaphores = kmap_atomic(page);
>  		memset(semaphores + GEN8_SEMAPHORE_OFFSET(engine->id, 0),
>  		       0, I915_NUM_ENGINES * gen8_semaphore_seqno_size);
>  		drm_clflush_virt_range(semaphores + GEN8_SEMAPHORE_OFFSET(engine->id, 0),
>  				       I915_NUM_ENGINES * gen8_semaphore_seqno_size);
> -		kunmap(page);
> +		kunmap_atomic(semaphores);
>  	}
>
>  	intel_write_status_page(engine, I915_GEM_HWS_INDEX, seqno);
>

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko