On Thu, 2021-11-04 at 16:10 +0200, Ville Syrjälä wrote:
> On Tue, Nov 02, 2021 at 12:32:14PM -0700, José Roberto de Souza wrote:
> > Changing the buffer in the middle of the scanout then entering an
> > period of flip idleness will cause part of the previous buffer being
> > diplayed to user when PSR is enabled.
> >
> > So here disabling PSR and scheduling activation during the next
> > sync flip.
> >
> > The async flip check that we had in PSR compute is not executed at
> > every flip so it was not doing anything useful and is also being
> > dropped here.
> >
> > v2:
> > - scheduling the PSR work in _intel_psr_post_plane_update()
> >
> > v3:
> > - only re enabling PSR when doing a sync flip
> >
> > Cc: Karthik B S <karthik.b.s@xxxxxxxxx>
> > Cc: Vandita Kulkarni <vandita.kulkarni@xxxxxxxxx>
> > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> > Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/display/intel_psr.c | 37 ++++++++++++++----------
> > 1 file changed, 21 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 9d589d471e335..b8fac53d57df1 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -731,12 +731,6 @@ static bool intel_psr2_sel_fetch_config_valid(struct intel_dp *intel_dp,
> > return false;
> > }
> >
> > - if (crtc_state->uapi.async_flip) {
> > - drm_dbg_kms(&dev_priv->drm,
> > - "PSR2 sel fetch not enabled, async flip enabled\n");
> > - return false;
> > - }
> > -
> > /* Wa_14010254185 Wa_14010103792 */
> > if (IS_TGL_DISPLAY_STEP(dev_priv, STEP_A0, STEP_C0)) {
> > drm_dbg_kms(&dev_priv->drm,
> > @@ -1780,36 +1774,47 @@ void intel_psr_pre_plane_update(struct intel_atomic_state *state,
> > if (psr->enabled && needs_to_disable)
> > intel_psr_disable_locked(intel_dp);
> >
> > + if (psr->enabled && crtc_state->uapi.async_flip)
> > + intel_psr_exit(intel_dp);
> > +
> > mutex_unlock(&psr->lock);
> > }
> > }
> >
> > static void _intel_psr_post_plane_update(const struct intel_atomic_state *state,
> > - const struct intel_crtc_state *crtc_state)
> > + const struct intel_crtc_state *old_crtc_state,
> > + const struct intel_crtc_state *new_crtc_state)
>
> Might make sense to change this to match how psr_pre_plane_update()
> works these days.
Will do as follow up.
>
> > {
> > struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > struct intel_encoder *encoder;
> >
> > - if (!crtc_state->has_psr)
> > + if (!new_crtc_state->has_psr)
> > return;
> >
> > for_each_intel_encoder_mask_with_psr(state->base.dev, encoder,
> > - crtc_state->uapi.encoder_mask) {
> > + new_crtc_state->uapi.encoder_mask) {
> > struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> > struct intel_psr *psr = &intel_dp->psr;
> >
> > mutex_lock(&psr->lock);
> >
> > - drm_WARN_ON(&dev_priv->drm, psr->enabled && !crtc_state->active_planes);
> > + drm_WARN_ON(&dev_priv->drm, psr->enabled &&
> > + !new_crtc_state->active_planes);
> >
> > /* Only enable if there is active planes */
> > - if (!psr->enabled && crtc_state->active_planes)
> > - intel_psr_enable_locked(intel_dp, crtc_state);
> > + if (!psr->enabled && new_crtc_state->active_planes)
> > + intel_psr_enable_locked(intel_dp, new_crtc_state);
>
> What prevents this guy from activating PSR while we're doing
> an async flip?
enabled != active, when doing a async flip it will set active = false but enabled will be kept on.
And to change the number of active_planes it will need to do a sync flip, so we are safe.
>
> >
> > /* Force a PSR exit when enabling CRC to avoid CRC timeouts */
> > - if (crtc_state->crc_enabled && psr->enabled)
> > + if (new_crtc_state->crc_enabled && psr->enabled)
> > psr_force_hw_tracking_exit(intel_dp);
> >
> > + /* Only re enabling PSR when doing a sync flip */
> > + if (psr->enabled && !psr->active &&
> > + old_crtc_state->uapi.async_flip &&
> > + !new_crtc_state->uapi.async_flip)
> > + schedule_work(&intel_dp->psr.work);
> > +
> > mutex_unlock(&psr->lock);
> > }
> > }
> > @@ -1817,15 +1822,15 @@ static void _intel_psr_post_plane_update(const struct intel_atomic_state *state,
> > void intel_psr_post_plane_update(const struct intel_atomic_state *state)
> > {
> > struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > - struct intel_crtc_state *crtc_state;
> > + struct intel_crtc_state *old_crtc_state, *new_crtc_state;
> > struct intel_crtc *crtc;
> > int i;
> >
> > if (!HAS_PSR(dev_priv))
> > return;
> >
> > - for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i)
> > - _intel_psr_post_plane_update(state, crtc_state);
> > + for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i)
> > + _intel_psr_post_plane_update(state, old_crtc_state, new_crtc_state);
> > }
> >
> > static int _psr2_ready_for_pipe_update_locked(struct intel_dp *intel_dp)
> > --
> > 2.33.1
>
