Thank You for the patch. This does the trick. No full modest because of
Mbus joining
Tested-by: Khaled Almahallawy <khaled.almahallawy@xxxxxxxxx>
On Thu, 2023-08-10 at 11:17 +0300, Stanislav Lisovskiy wrote:
> Currently we can't change MBUS join status without doing a modeset,
> because we are lacking mechanism to synchronize those with vblank.
> However then this means that we can't do a fastset, if there is a
> need
> to change MBUS join state. Fix that by implementing such change.
> We already call correspondent check and update at pre_plane dbuf
> update,
> so the only thing left is to have a non-modeset version of that.
> If active pipes stay the same then fastset is possible and only MBUS
> join state/ddb allocation updates would be committed.
>
> v2: Implement additional changes according to BSpec.
> Vblank wait is needed after MBus/Dbuf programming in case if
> no modeset is done and we are switching from single to multiple
> displays, i.e mbus join state switches from "joined" to "non-
> joined"
> state. Otherwise vblank wait is not needed according to spec.
>
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/skl_watermark.c | 36 ++++++++++++++++
> ----
> 1 file changed, 29 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c
> b/drivers/gpu/drm/i915/display/skl_watermark.c
> index 063929a42a42f..4fbc74e800217 100644
> --- a/drivers/gpu/drm/i915/display/skl_watermark.c
> +++ b/drivers/gpu/drm/i915/display/skl_watermark.c
> @@ -2614,13 +2614,6 @@ skl_compute_ddb(struct intel_atomic_state
> *state)
> if (ret)
> return ret;
>
> - if (old_dbuf_state->joined_mbus != new_dbuf_state-
> >joined_mbus) {
> - /* TODO: Implement vblank synchronized MBUS
> joining changes */
> - ret = intel_modeset_all_pipes(state, "MBUS
> joining change");
> - if (ret)
> - return ret;
> - }
> -
> drm_dbg_kms(&i915->drm,
> "Enabled dbuf slices 0x%x -> 0x%x (total
> dbuf slices 0x%x), mbus joined? %s->%s\n",
> old_dbuf_state->enabled_slices,
> @@ -3528,6 +3521,35 @@ void intel_dbuf_pre_plane_update(struct
> intel_atomic_state *state)
> gen9_dbuf_slices_update(i915,
> old_dbuf_state->enabled_slices |
> new_dbuf_state->enabled_slices);
> +
> + /*
> + * If we are not doing a modeset, that means we must
> synchronize
> + * our MBUS configuration changes with vblank.
> + * According to MBus programming section of BSpec, we must wait
> for vblank
> + * on active crtc, which was single display, when switching
> from single
> + * display(mbus joined) to additional multiple displays(mbus
> not joined)
> + * after Mbus/Dbuf slice programming is done.
> + */
> + if (!state->modeset && !new_dbuf_state->joined_mbus &&
> old_dbuf_state->joined_mbus) {
> + struct intel_crtc *crtc;
> + struct intel_crtc_state *new_crtc_state,
> *old_crtc_state;
> + int i;
> +
> + for_each_oldnew_intel_crtc_in_state(state, crtc,
> old_crtc_state, new_crtc_state, i) {
> + /*
> + * Need to wait for vblank only if crtc was
> active prior to that change,
> + * i.e this is a scenario when we switch from
> single display to multiple
> + * displays, without doing a full modeset and
> it still stays on, according
> + * to BSpec only in that case we need to wait
> for vblank on that previously
> + * single display. Otherwise no wait is needed.
> Rest of the cases, are not
> + * possible without a modeset anyway.
> + */
> + if (!new_crtc_state->hw.active ||
> !old_crtc_state->hw.active)
> + continue;
> +
> + intel_crtc_wait_for_next_vblank(crtc);
> + }
> + }
> }
>
> void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
