Re: [PATCH v2 4/4] drm/i915/psr: Add poll for checking PSR is idle before starting update

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

On Wed, Aug 06, 2025 at 08:22:13AM +0300, Jouni Högander wrote:
> We are currently observing crc failures after we started using dsb for PSR
> updates as well. This seems to happen because PSR HW is still sending
> couple of updates using old framebuffers on wake-up.
> 
> Fix this by adding poll ensuring PSR is idle before starting update.
> 
> Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index c1a3a95c65f0..411c74c73eae 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -7271,6 +7271,8 @@ static void intel_atomic_dsb_finish(struct intel_atomic_state *state,
>  		intel_psr_trigger_frame_change_event(new_crtc_state->dsb_commit,
>  						     state, crtc);
>  
> +		intel_psr_wait_for_idle_dsb(new_crtc_state);
> +
>  		if (new_crtc_state->use_dsb)
>  			intel_dsb_vblank_evade(state, new_crtc_state->dsb_commit);

How come the 'evade scanline 0 + normal evasion' in intel_dsb_vblank_evade()
is not enough here?

-- 
Ville Syrjälä
Intel