[PATCH 2/2] drm/amd/display: use drm_crtc_vblank_on_config()

[Daniel Vetter]

On Thu, Jul 25, 2024 at 04:51:09PM -0400, Hamza Mahfooz wrote:
> Hook up drm_crtc_vblank_on_config() in amdgpu_dm. So, that we can enable
> PSR and other static screen optimizations more quickly, while avoiding
> stuttering issues that are accompanied by the following dmesg error:
> 
> [drm:dc_dmub_srv_wait_idle [amdgpu]] *ERROR* Error waiting for DMUB idle: status=3
> 
> This also allows us to mimic how vblanking is handled by the windows
> amdgpu driver.
> 
> Signed-off-by: Hamza Mahfooz <hamza.mahfooz at amd.com>
> ---
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 49 +++++++++++++++++--
>  1 file changed, 44 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 07e373deb814..780e31a2d456 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -7952,7 +7952,7 @@ static int amdgpu_dm_encoder_init(struct drm_device *dev,
>  
>  static void manage_dm_interrupts(struct amdgpu_device *adev,
>  				 struct amdgpu_crtc *acrtc,
> -				 bool enable)
> +				 struct dm_crtc_state *acrtc_state)
>  {
>  	/*
>  	 * We have no guarantee that the frontend index maps to the same
> @@ -7964,9 +7964,47 @@ static void manage_dm_interrupts(struct amdgpu_device *adev,
>  		amdgpu_display_crtc_idx_to_irq_type(
>  			adev,
>  			acrtc->crtc_id);
> +	struct dc_crtc_timing *timing;
> +	int vsync_rate_hz;
> +	int offdelay = 30;
> +
> +	if (acrtc_state) {
> +		timing = &acrtc_state->stream->timing;
> +
> +		vsync_rate_hz = div64_u64(div64_u64((timing->pix_clk_100hz *
> +						     (uint64_t)100),
> +						    timing->v_total),
> +					  timing->h_total);
> +
> +		if (amdgpu_ip_version(adev, DCE_HWIP, 0) >=
> +		    IP_VERSION(3, 5, 0) && (adev->flags & AMD_IS_APU)) {
> +			if (vsync_rate_hz)
> +				/* at least 2 frames */
> +				offdelay = 2000 / vsync_rate_hz + 1;
> +
> +			if (acrtc_state->stream->link->psr_settings.psr_version <
> +			    DC_PSR_VERSION_UNSUPPORTED) {
> +				const struct drm_vblank_crtc_config config = {
> +					.offdelay_ms = offdelay,
> +					.disable_immediate = false
> +				};
> +
> +				drm_crtc_vblank_on_config(&acrtc->base,
> +							  &config);
> +			} else {
> +				const struct drm_vblank_crtc_config config = {
> +					.offdelay_ms = 0,
> +					.disable_immediate = true

Uh, I think it'd be better to use drm_crtc_vblank_on() here and then have
a 2nd patch which re-enables the immediate vblank disabling and references
the right revert for context.

Plus this feels like a demidlayer hack, but I don't understand enough DC
code to know a better place ...
-Sima

> +				};
> +
> +				drm_crtc_vblank_on_config(&acrtc->base,
> +							  &config);
> +			}
> +
> +		} else {
> +			drm_crtc_vblank_on(&acrtc->base);
> +		}
>  
> -	if (enable) {
> -		drm_crtc_vblank_on(&acrtc->base);
>  		amdgpu_irq_get(
>  			adev,
>  			&adev->pageflip_irq,
> @@ -8947,7 +8985,7 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
>  		if (old_crtc_state->active &&
>  		    (!new_crtc_state->active ||
>  		     drm_atomic_crtc_needs_modeset(new_crtc_state))) {
> -			manage_dm_interrupts(adev, acrtc, false);
> +			manage_dm_interrupts(adev, acrtc, NULL);
>  			dc_stream_release(dm_old_crtc_state->stream);
>  		}
>  	}
> @@ -9465,7 +9503,8 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
>  		     drm_atomic_crtc_needs_modeset(new_crtc_state))) {
>  			dc_stream_retain(dm_new_crtc_state->stream);
>  			acrtc->dm_irq_params.stream = dm_new_crtc_state->stream;
> -			manage_dm_interrupts(adev, acrtc, true);
> +			manage_dm_interrupts(adev, acrtc,
> +					     to_dm_crtc_state(new_crtc_state));
>  		}
>  		/* Handle vrr on->off / off->on transitions */
>  		amdgpu_dm_handle_vrr_transition(dm_old_crtc_state, dm_new_crtc_state);
> -- 
> 2.45.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch