On Thu, Jun 10, 2021 at 02:50:36PM +0200, Maxime Ripard wrote:
> Hi
>
> On Tue, Jun 08, 2021 at 07:43:17PM +0200, Werner Sembach wrote:
> > This commits implements the "active bpc" drm property for the Intel GPU driver.
> >
> > Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/display/intel_display.c | 14 ++++++++++++++
> > drivers/gpu/drm/i915/display/intel_dp.c | 8 ++++++--
> > drivers/gpu/drm/i915/display/intel_dp_mst.c | 4 +++-
> > drivers/gpu/drm/i915/display/intel_hdmi.c | 4 +++-
> > 4 files changed, 26 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > index 64e9107d70f7..50c11b8770a7 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -10388,6 +10388,9 @@ static int intel_atomic_commit(struct drm_device *dev,
> > {
> > struct intel_atomic_state *state = to_intel_atomic_state(_state);
> > struct drm_i915_private *dev_priv = to_i915(dev);
> > + struct drm_connector *connector;
> > + struct drm_connector_state *new_conn_state;
> > + int i;
> > int ret = 0;
> >
> > state->wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);
> > @@ -10456,6 +10459,17 @@ static int intel_atomic_commit(struct drm_device *dev,
> > intel_shared_dpll_swap_state(state);
> > intel_atomic_track_fbs(state);
> >
> > + /* Extract information from crtc to communicate it to userspace as connector properties */
> > + for_each_new_connector_in_state(&state->base, connector, new_conn_state, i) {
> > + struct intel_crtc *crtc = to_intel_crtc(new_conn_state->crtc);
> > + if (crtc) {
> > + struct intel_crtc_state *new_crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
> > + new_conn_state->active_bpc = new_crtc_state->pipe_bpp / 3;
> > + }
> > + else
> > + new_conn_state->active_bpc = 0;
> > + }
> > +
>
> This seems fairly intrusive, but also commit / commit_tail might not be
> the best place to put this, we want to support it at the connector
> level.
>
> Indeed, this will cause some issue if your HDMI output is a bridge for
> example, where the commit will be in an entirely different driver that
> has no dependency on the HDMI controller one.
>
> I think it would be best to do that assignment in atomic_check. That
> way, if the userspace does a commit with DRM_MODE_ATOMIC_TEST_ONLY it
> would know what the output state would have been like.
DRM_MODE_ATOMIC_TEST_ONLY isn't allowed to change anything.
--
Ville Syrjälä
Intel
