Re: [PATCH 08/19] drm/i915/dp: Add a helper to decide if AS SDP can be used

Ville Syrjälä
2026-03-30T19:40:35Z

On Mon, Mar 30, 2026 at 09:21:42PM +0300, Ville Syrjälä wrote:
> On Mon, Mar 30, 2026 at 09:36:45AM +0530, Ankit Nautiyal wrote:
> > Add a helper that determines whether AS SDP can be used for the
> > current DP configuration. For now this is true only when the sink
> > supports AS SDP and VRR is enabled, but more conditions may be added
> > later.
> >
> > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> > ---
> > drivers/gpu/drm/i915/display/intel_dp.c | 11 ++++++++++-
> > 1 file changed, 10 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 499850c2abcf..7ca3f9d583db 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -3124,6 +3124,15 @@ static void intel_dp_compute_vsc_colorimetry(const struct intel_crtc_state *crtc
> > vsc->content_type = DP_CONTENT_TYPE_NOT_DEFINED;
> > }
> >
> > +static bool intel_dp_can_use_as_sdp(struct intel_dp *intel_dp,
> > + struct intel_crtc_state *crtc_state)

Hmm. Maybe the name should be .._need_as_sdp() or something like that
instead. I can imagine many cases when we could use the AS SDP but don't
have to.

> > +{
> > + if (!intel_dp->as_sdp_supported)
> > + return false;
> > +
>
> Could have a FIXME here about fastset being borked with this. Didn't
> read far enough in the series yet to see if you did anything about that.
>
> Either way
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> > + return crtc_state->vrr.enable;
> > +}
> > +
> > static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
> > struct intel_crtc_state *crtc_state)
> > {
> > @@ -3131,7 +3140,7 @@ static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
> > const struct drm_display_mode *adjusted_mode =
> > &crtc_state->hw.adjusted_mode;
> >
> > - if (!crtc_state->vrr.enable || !intel_dp->as_sdp_supported)
> > + if (!intel_dp_can_use_as_sdp(intel_dp, crtc_state))
> > return;
> >
> > crtc_state->infoframes.enable |= intel_hdmi_infoframe_enable(DP_SDP_ADAPTIVE_SYNC);
> > --
> > 2.45.2
>
> --
> Ville Syrjälä
> Intel

--
Ville Syrjälä
Intel