Re: [PATCH 08/10] drm/i915/rps: postpone i915 fence check to boost

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Nov 14, 2025 at 12:26:47PM +0200, Jani Nikula wrote:
> Make the RPS boost code independent of i915 request code by moving the
> dma_fence_is_i915() check to the RPS boost call.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> 
> ---
> 
> I'm not actually sure what the non-i915 fences would be here, and what
> kind of overhead they would cause.

The fence could be from another GPU driver that did the rendering,
and then we can't convert the fence to i915 request.

At some point we should probably look into using the fence
.set_deadline() stuff instead of this "boost when late"
approach, but that's one of those things that probably needs
some amount of hand tuning, so real work required.

Anyways I think this should be fine, we just set up the vblank
miss thingy even for non-i915 fences now and then do nothing
if it triggers.

aReviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_display_rps.c | 4 ----
>  drivers/gpu/drm/i915/gt/intel_rps.c              | 7 ++++++-
>  2 files changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_rps.c b/drivers/gpu/drm/i915/display/intel_display_rps.c
> index e70c4f0eab80..86e757423c0a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_rps.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_rps.c
> @@ -9,7 +9,6 @@
>  #include <drm/drm_vblank.h>
>  
>  #include "i915_reg.h"
> -#include "i915_request.h"
>  #include "intel_display_core.h"
>  #include "intel_display_irq.h"
>  #include "intel_display_rps.h"
> @@ -49,9 +48,6 @@ void intel_display_rps_boost_after_vblank(struct drm_crtc *crtc,
>  	if (!intel_parent_rps_available(display))
>  		return;
>  
> -	if (!dma_fence_is_i915(fence))
> -		return;
> -
>  	if (DISPLAY_VER(display) < 6)
>  		return;
>  
> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
> index 61d746bda462..05b21de6c24b 100644
> --- a/drivers/gpu/drm/i915/gt/intel_rps.c
> +++ b/drivers/gpu/drm/i915/gt/intel_rps.c
> @@ -2917,7 +2917,12 @@ EXPORT_SYMBOL_GPL(i915_gpu_turbo_disable);
>  
>  static void boost(struct dma_fence *fence)
>  {
> -	struct i915_request *rq = to_request(fence);
> +	struct i915_request *rq;
> +
> +	if (!dma_fence_is_i915(fence))
> +		return;
> +
> +	rq = to_request(fence);
>  
>  	/*
>  	 * If we missed the vblank, but the request is already running it
> -- 
> 2.47.3

-- 
Ville Syrjälä
Intel