[PATCH 18/22] drm/i915: Handle joined pipes inside hsw_crtc_disable()

[Murthy, Arun R]

> -----Original Message-----
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Sent: Wednesday, April 3, 2024 1:20 AM
> To: Murthy, Arun R <arun.r.murthy at intel.com>
> Cc: intel-gfx at lists.freedesktop.org
> Subject: Re: [PATCH 18/22] drm/i915: Handle joined pipes inside
> hsw_crtc_disable()
> 
> On Mon, Apr 01, 2024 at 06:46:20AM +0000, Murthy, Arun R wrote:
> >
> > > -----Original Message-----
> > > From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf
> > > Of Ville Syrjala
> > > Sent: Friday, March 29, 2024 6:43 AM
> > > To: intel-gfx at lists.freedesktop.org
> > > Subject: [PATCH 18/22] drm/i915: Handle joined pipes inside
> > > hsw_crtc_disable()
> > >
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > >
> > > Reorganize the crtc disable path to only deal with the master
> > > pipes/transcoders in intel_old_crtc_state_disables() and offload the
> > > handling of joined pipes to hsw_crtc_disable().
> > > This makes the whole thing much more sensible since we can actually
> > > control the order in which we do the per-pipe vs.
> > > per-transcoder modeset steps.
> > >
> > > v2: Use the name 'pipe_crtc' for the per-pipe crtc pointer
> > >
> > > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_display.c | 64
> > > ++++++++++++--------
> > >  1 file changed, 39 insertions(+), 25 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > index 58ee40786d5c..c15ea046c62a 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -1791,29 +1791,28 @@ static void hsw_crtc_disable(struct
> > > intel_atomic_state *state,
> > >  	const struct intel_crtc_state *old_crtc_state =
> > >  		intel_atomic_get_old_crtc_state(state, crtc);
> > >  	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> > > +	struct intel_crtc *pipe_crtc;
> > >
> > >  	/*
> > >  	 * FIXME collapse everything to one hook.
> > >  	 * Need care with mst->ddi interactions.
> > >  	 */
> > > -	if (!intel_crtc_is_bigjoiner_slave(old_crtc_state)) {
> > > -		intel_encoders_disable(state, crtc);
> > > -		intel_encoders_post_disable(state, crtc);
> > > -	}
> > > -
> > > -	intel_disable_shared_dpll(old_crtc_state);
> > > +	intel_encoders_disable(state, crtc);
> > > +	intel_encoders_post_disable(state, crtc);
> > >
> > > -	if (!intel_crtc_is_bigjoiner_slave(old_crtc_state)) {
> > > -		struct intel_crtc *slave_crtc;
> > > +	for_each_intel_crtc_in_pipe_mask(&i915->drm, pipe_crtc,
> > > +
> > > intel_crtc_joined_pipe_mask(old_crtc_state)) {
> > > +		const struct intel_crtc_state *old_pipe_crtc_state =
> > > +			intel_atomic_get_old_crtc_state(state, pipe_crtc);
> > >
> > > -		intel_encoders_post_pll_disable(state, crtc);
> > > +		intel_disable_shared_dpll(old_pipe_crtc_state);
> > > +	}
> >
> > As per the sequence is considered, should the pll be disabled prior to disabling
> the encoders and then followed by post_pll_disable?
> 
> The correct disable order is:
> 1. encoder disable()
> 2. disable transcoder/etc. (nop for hsw+ as that stuff
>    has been sucked into the encoder hooks) 3. encoder post_disable() 4. pll
> disable 5. encoder post_pll_disable()
> 
> which we should be following here, thouh the diff is rather hard to read due to
> the indentation changes.
> 
Thanks for the clarification. I verified in the source code.

Reviewed-by: Arun R Murthy <arun.r.murthy at intel.com>

Thanks and Regards,
Arun R Murthy
--------------------
> --
> Ville Syrjälä
> Intel