[PATCH v4 09/13] drm/i915/display: Don't use DSB if psr mode changing

[Hogander, Jouni]

On Fri, 2025-01-24 at 13:53 +0200, Ville Syrjälä wrote:
> On Fri, Jan 24, 2025 at 12:56:20PM +0200, Jouni Högander wrote:
> > Changing PSR mode using DSB is not implemented. Do not use DSB when
> > PSR
> > mode is changing.
> > 
> > Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
> > Reviewed-by: Animesh Manna <animesh.manna at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > b/drivers/gpu/drm/i915/display/intel_display.c
> > index 3ac1cc9ac08a8..a189aa437d972 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -7682,7 +7682,8 @@ static void intel_atomic_dsb_finish(struct
> > intel_atomic_state *state,
> >  		!new_crtc_state->scaler_state.scaler_users &&
> >  		!old_crtc_state->scaler_state.scaler_users &&
> >  		!intel_crtc_needs_modeset(new_crtc_state) &&
> > -		!intel_crtc_needs_fastset(new_crtc_state);
> > +		!intel_crtc_needs_fastset(new_crtc_state) &&
> > +		!intel_psr_is_psr_mode_changing(old_crtc_state,
> > new_crtc_state);
> 
> Hmm. Doesn't all that imply a fastset anyway

PSR/PR doesn't imply fastset.

At the time of enabling PSR/PR crtc_state->has_psr is true at this
point, but PSR is not yet enabled. It gets enabled only in 
pre_plane_update. Also in hsw_activate_psr2 and
dg2_panel_replay_activate we are writing PSR2_MAN_TRK_CTL.

BR,

Jouni Högander

> , and/or maybe all the
> PSR stuff happens in the {pre,post}_plane_update() stuff? In which
> case it shouldn't really matter for the stuff that the DSB does.
> 
> >  
> >  	if (!new_crtc_state->use_dsb && !new_crtc_state-
> > >dsb_color_vblank)
> >  		return;
> > -- 
> > 2.43.0
>