[PATCH 04/14] drm/i915/ddi: For an active output call the DP encoder sync_state() only for DP

[Imre Deak]

On Tue, Jul 23, 2024 at 11:28:33AM +0300, Kandpal, Suraj wrote:
> 
> 
> > -----Original Message-----
> > From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Imre
> > Deak
> > Sent: Monday, July 22, 2024 10:25 PM
> > To: intel-gfx at lists.freedesktop.org
> > Subject: [PATCH 04/14] drm/i915/ddi: For an active output call the DP
> > encoder sync_state() only for DP
> >
> > If the DDI encoder output is enabled in HDMI mode there is no point in
> > calling intel_dp_sync_state(), as in that case the DPCD initialization will fail -
> > as expected - with AUX timeouts. Prevent calling the hook in this case.
> >
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_ddi.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index a07aca96e5517..11ee4406dce8f 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -4172,7 +4172,8 @@ static void intel_ddi_sync_state(struct
> > intel_encoder *encoder,
> >               intel_tc_port_sanitize_mode(enc_to_dig_port(encoder),
> >                                           crtc_state);
> >
> > -     if (intel_encoder_is_dp(encoder))
> > +     if ((crtc_state && intel_crtc_has_dp_encoder(crtc_state)) ||
> > +         (!crtc_state && intel_encoder_is_dp(encoder)))
> 
> So we are trying to avoid calling  intel_dp_sync_state incase
> intel_encoder_is_dp returns INTEL_OUTPUT_DDI in that case why are we
> still keeping the check intel_encoder_is_dp when crtc_state is not
> present.

intel_encoder_is_dp() returns true if a DP connector is registered using
this DDI encoder. If the output is disabled (so crtc_state==NULL) that's
the only way to determine if the encoder may be used for DP (unless an
HDMI connector is also registered using this same encoder and that's
what is actually used on the given platform). In case the output is
enabled the DP/HDMI mode in crtc_state gives the same answer, but by
checking that instead we avoid calling the DP specific hook if the
encoder is used by HDMI.

> Regards,
> Suraj Kandpal
> 
> >               intel_dp_sync_state(encoder, crtc_state);  }
> >
> > --
> > 2.44.2
>