[Intel-gfx] [PATCH 3/7] drm/i915/display: Add new fb_op_origin type and use it to optimize power savings

Ville Syrjälä ville.syrjala at linux.intel.com
Fri Sep 24 14:39:59 UTC 2021


On Thu, Sep 23, 2021 at 12:46:13PM -0700, José Roberto de Souza wrote:
> intel_prepare_plane_fb() was calling i915_gem_object_flush_frontbuffer()
> with the generic ORIGIN_DIRTYFB, what was causing
> PSR, FBC and DRRS to do their frontbuffer rendering in a framebuffer
> that will be flipped.
> 
> Not handling this call as frontbuffer rendering allow us to save
> more power with all 3 features.
> 
> Same applies when allocating a framebuffer for fbdev emulation, after
> allocation userspace will draw on it and trigger invaldate/flush calls
> with ORIGIN_DIRTYFB.
> 
> Cc: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c     | 2 +-
>  drivers/gpu/drm/i915/display/intel_drrs.c        | 5 ++++-
>  drivers/gpu/drm/i915/display/intel_drrs.h        | 4 +++-
>  drivers/gpu/drm/i915/display/intel_fbc.c         | 2 +-
>  drivers/gpu/drm/i915/display/intel_fbdev.c       | 2 +-
>  drivers/gpu/drm/i915/display/intel_frontbuffer.c | 2 +-
>  drivers/gpu/drm/i915/display/intel_frontbuffer.h | 1 +
>  drivers/gpu/drm/i915/display/intel_psr.c         | 5 ++++-
>  8 files changed, 16 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index f27c294beb926..ecf8c69473e38 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -10666,7 +10666,7 @@ intel_prepare_plane_fb(struct drm_plane *_plane,
>  		return ret;
>  
>  	i915_gem_object_wait_priority(obj, 0, &attr);
> -	i915_gem_object_flush_frontbuffer(obj, ORIGIN_DIRTYFB);
> +	i915_gem_object_flush_frontbuffer(obj, ORIGIN_PREPARE_FB);

I think this should just get nuked. See
https://patchwork.freedesktop.org/patch/432166/?series=89824&rev=1

Unfortunately I wasn't able to get past glk's semi-borked
FBC with that yet.

>  
>  	if (!new_plane_state->uapi.fence) { /* implicit fencing */
>  		struct dma_fence *fence;
> diff --git a/drivers/gpu/drm/i915/display/intel_drrs.c b/drivers/gpu/drm/i915/display/intel_drrs.c
> index c1439fcb5a959..46828222a098b 100644
> --- a/drivers/gpu/drm/i915/display/intel_drrs.c
> +++ b/drivers/gpu/drm/i915/display/intel_drrs.c
> @@ -373,8 +373,11 @@ void intel_drrs_invalidate(struct drm_i915_private *dev_priv,
>   * Dirty frontbuffers relevant to DRRS are tracked in busy_frontbuffer_bits.
>   */
>  void intel_drrs_flush(struct drm_i915_private *dev_priv,
> -		      unsigned int frontbuffer_bits)
> +		      unsigned int frontbuffer_bits, enum fb_op_origin origin)
>  {
> +	if (origin == ORIGIN_PREPARE_FB)
> +		return;
> +
>  	intel_drrs_frontbuffer_update(dev_priv, frontbuffer_bits, false);
>  }
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_drrs.h b/drivers/gpu/drm/i915/display/intel_drrs.h
> index 9ec9c447211af..e69528a98a9c2 100644
> --- a/drivers/gpu/drm/i915/display/intel_drrs.h
> +++ b/drivers/gpu/drm/i915/display/intel_drrs.h
> @@ -8,6 +8,8 @@
>  
>  #include <linux/types.h>
>  
> +#include "intel_frontbuffer.h"
> +
>  struct drm_i915_private;
>  struct intel_atomic_state;
>  struct intel_crtc;
> @@ -24,7 +26,7 @@ void intel_drrs_update(struct intel_dp *intel_dp,
>  void intel_drrs_invalidate(struct drm_i915_private *dev_priv,
>  			   unsigned int frontbuffer_bits);
>  void intel_drrs_flush(struct drm_i915_private *dev_priv,
> -		      unsigned int frontbuffer_bits);
> +		      unsigned int frontbuffer_bits, enum fb_op_origin origin);
>  void intel_drrs_page_flip(struct intel_atomic_state *state,
>  			  struct intel_crtc *crtc);
>  void intel_drrs_compute_config(struct intel_dp *intel_dp,
> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> index b1c1a23c36be3..56c2de2994602 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> @@ -1155,7 +1155,7 @@ void intel_fbc_flush(struct drm_i915_private *dev_priv,
>  
>  	fbc->busy_bits &= ~frontbuffer_bits;
>  
> -	if (origin == ORIGIN_FLIP)
> +	if (origin == ORIGIN_FLIP || origin == ORIGIN_PREPARE_FB)
>  		goto out;
>  
>  	if (!fbc->busy_bits && fbc->crtc &&
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 60d3ded270476..3097658938ae2 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -230,7 +230,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
>  		goto out_unlock;
>  	}
>  
> -	intel_frontbuffer_flush(to_frontbuffer(ifbdev), ORIGIN_DIRTYFB);
> +	intel_frontbuffer_flush(to_frontbuffer(ifbdev), ORIGIN_PREPARE_FB);
>  
>  	info = drm_fb_helper_alloc_fbi(helper);
>  	if (IS_ERR(info)) {
> diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
> index 0492446cd04ad..a88c147d6b523 100644
> --- a/drivers/gpu/drm/i915/display/intel_frontbuffer.c
> +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
> @@ -92,7 +92,7 @@ static void frontbuffer_flush(struct drm_i915_private *i915,
>  	trace_intel_frontbuffer_flush(frontbuffer_bits, origin);
>  
>  	might_sleep();
> -	intel_drrs_flush(i915, frontbuffer_bits);
> +	intel_drrs_flush(i915, frontbuffer_bits, origin);
>  	intel_psr_flush(i915, frontbuffer_bits, origin);
>  	intel_fbc_flush(i915, frontbuffer_bits, origin);
>  }
> diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.h b/drivers/gpu/drm/i915/display/intel_frontbuffer.h
> index 4b977c1e4d52b..950030950b0f9 100644
> --- a/drivers/gpu/drm/i915/display/intel_frontbuffer.h
> +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.h
> @@ -37,6 +37,7 @@ enum fb_op_origin {
>  	ORIGIN_CS,
>  	ORIGIN_FLIP,
>  	ORIGIN_DIRTYFB,
> +	ORIGIN_PREPARE_FB,
>  };
>  
>  struct intel_frontbuffer {
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> index ba2da689920f9..1cc4130dec7b1 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -2073,7 +2073,7 @@ void intel_psr_invalidate(struct drm_i915_private *dev_priv,
>  {
>  	struct intel_encoder *encoder;
>  
> -	if (origin == ORIGIN_FLIP)
> +	if (origin == ORIGIN_FLIP || origin == ORIGIN_PREPARE_FB)
>  		return;
>  
>  	for_each_intel_encoder_with_psr(&dev_priv->drm, encoder) {
> @@ -2148,6 +2148,9 @@ void intel_psr_flush(struct drm_i915_private *dev_priv,
>  {
>  	struct intel_encoder *encoder;
>  
> +	if (origin == ORIGIN_PREPARE_FB)
> +		return;
> +
>  	for_each_intel_encoder_with_psr(&dev_priv->drm, encoder) {
>  		unsigned int pipe_frontbuffer_bits = frontbuffer_bits;
>  		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> -- 
> 2.33.0

-- 
Ville Syrjälä
Intel


More information about the Intel-gfx mailing list