On Mon, Jul 11, 2022 at 09:16:01AM +0300, Jouni Högander wrote:
> Currently PSR is left enabled when all planes are disabled if there
> is no attached encoder in new state. This seems to be causing FIFO
> underruns.
>
> Fix this by checking if old and new crtc encoder masks are differing.
> PSR is disabled for encoders not in new crtc state encoder mask.
>
> Cc: Mika Kahola <mika.kah...@intel.com>
> Reported-by: Stanislav Lisovskiy <stanislav.lisovs...@intel.com>
> Signed-off-by: Jouni Högander <jouni.hogan...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_psr.c | 72 +++++++++++++++++-------
> 1 file changed, 51 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index e6a870641cd2..710cc31ace22 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -1863,36 +1863,66 @@ void intel_psr_pre_plane_update(struct
> intel_atomic_state *state,
> struct intel_crtc *crtc)
> {
> struct drm_i915_private *i915 = to_i915(state->base.dev);
> - const struct intel_crtc_state *crtc_state =
> - intel_atomic_get_new_crtc_state(state, crtc);
> + struct intel_crtc_state *new_crtc_state, *old_crtc_state;
> struct intel_encoder *encoder;
> + struct intel_dp *intel_dp;
> + struct intel_psr *psr;
> + int i;
>
> if (!HAS_PSR(i915))
> return;
>
> - for_each_intel_encoder_mask_with_psr(state->base.dev, encoder,
> - crtc_state->uapi.encoder_mask) {
> - struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> - struct intel_psr *psr = &intel_dp->psr;
> - bool needs_to_disable = false;
> -
> - mutex_lock(&psr->lock);
> -
> + for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
> + new_crtc_state, i) {
> /*
> - * Reasons to disable:
> - * - PSR disabled in new state
> - * - All planes will go inactive
> - * - Changing between PSR versions
> + * Check if encoder exists in new state and disable
> + * psr if it doesn't. Otherwise we will end update
> + * having all planes disabled and psr enabled which
> + * seems to be causing problems.
> */
> - needs_to_disable |= intel_crtc_needs_modeset(crtc_state);
> - needs_to_disable |= !crtc_state->has_psr;
> - needs_to_disable |= !crtc_state->active_planes;
> - needs_to_disable |= crtc_state->has_psr2 != psr->psr2_enabled;
> + if (old_crtc_state->uapi.encoder_mask !=
> new_crtc_state->uapi.encoder_mask) {
> + for_each_intel_encoder_mask_with_psr(state->base.dev,
> encoder,
> +
> old_crtc_state->uapi.encoder_mask) {
> + intel_dp = enc_to_intel_dp(encoder);
> + psr = &intel_dp->psr;
>
> - if (psr->enabled && needs_to_disable)
> - intel_psr_disable_locked(intel_dp);
> + if (new_crtc_state->uapi.encoder_mask &
> + drm_encoder_mask(&(encoder)->base))
> + continue;
>
> - mutex_unlock(&psr->lock);
> + mutex_lock(&psr->lock);
> +
> + if (psr->enabled)
> + intel_psr_disable_locked(intel_dp);
> +
> + mutex_unlock(&psr->lock);
> + }
> + }
> + for_each_intel_encoder_mask_with_psr(state->base.dev, encoder,
> +
> new_crtc_state->uapi.encoder_mask) {
> + bool needs_to_disable = false;
> +
> + intel_dp = enc_to_intel_dp(encoder);
> + psr = &intel_dp->psr;
> +
> + mutex_lock(&psr->lock);
> +
> + /*
> + * Reasons to disable:
> + * - PSR disabled in new state
> + * - All planes will go inactive
> + * - Changing between PSR versions
> + */
> + needs_to_disable |=
> intel_crtc_needs_modeset(new_crtc_state);
> + needs_to_disable |= !new_crtc_state->has_psr;
> + needs_to_disable |= !new_crtc_state->active_planes;
> + needs_to_disable |= new_crtc_state->has_psr2 !=
> psr->psr2_enabled;
> +
> + if (psr->enabled && needs_to_disable)
> + intel_psr_disable_locked(intel_dp);
> +
> + mutex_unlock(&psr->lock);
> + }
> }
> }
Looks correct to me, the only thing that we could probable unite both
for_each_intel_encoder_mask_with_psr
cycles and also then get rid of if (old_crtc_state->uapi.encoder_mask !=
new_crtc_state->uapi.encoder_mask) check by
doing something like:
old_new_encoder_mask = old_crtc_state->uapi.encoder_mask |
new_crtc_state->uapi.encoder_mask;
for_each_intel_encoder_mask_with_psr(state->base.dev, encoder,
old_new_encoder_mask) {
bool needs_to_disable = false;
intel_dp = enc_to_intel_dp(encoder);
psr = &intel_dp->psr;
mutex_lock(&psr->lock);
needs_to_disable |= intel_crtc_needs_modeset(new_crtc_state);
needs_to_disable |= !new_crtc_state->has_psr;
needs_to_disable |= !new_crtc_state->active_planes;
needs_to_disable |= new_crtc_state->has_psr2 != psr->psr2_enabled;
/* Check if this encoder isn't present in new mask */
needs_to_disable |= !(new_crtc_state->uapi.encoder_mask &
drm_encoder_mask(&(encoder)->base));
if (psr->enabled && needs_to_disable)
intel_psr_disable_locked(intel_dp);
mutex_unlock(&psr_lock);
}
So basically we make non-presence of the encoder in new mask to be just one
more check
for needs_to_disable and have a single place where we turn it off..
Stan
>
> --
> 2.25.1
>
