> -----Original Message-----
> From: Intel-gfx <intel-gfx-boun...@lists.freedesktop.org> On Behalf Of Ville
> Syrjala
> Sent: Wednesday, March 27, 2024 3:40 AM
> To: intel-gfx@lists.freedesktop.org
> Subject: [PATCH v2 1/3] drm/i915/cdclk: Fix CDCLK programming order when
> pipes are active
>
> From: Ville Syrjälä <ville.syrj...@linux.intel.com>
>
> Currently we always reprogram CDCLK from the
> intel_set_cdclk_pre_plane_update() when using squahs/crawl.
Nitpick: Typo in squash
Change Looks Good to me.
Reviewed-by: Uma Shankar <uma.shan...@intel.com>
> The code only works correctly for the cd2x update or full modeset cases, and
> it
> was simply never updated to deal with squash/crawl.
>
> If the CDCLK frequency is increasing we must reprogram it before we do
> anything
> else that might depend on the new higher frequency, and conversely we must not
> decrease the frequency until everything that might still depend on the old
> higher
> frequency has been dealt with.
>
> Since cdclk_state->pipe is only relevant when doing a cd2x update we can't
> use it
> to determine the correct sequence during squash/crawl. To that end introduce
> cdclk_state->disable_pipes which simply indicates that we must perform the
> update while the pipes are disable (ie. during
> intel_set_cdclk_pre_plane_update()). Otherwise we use the same old vs. new
> CDCLK frequency comparsiong as for cd2x updates.
>
> The only remaining problem case is when the voltage_level needs to increase
> due
> to a DDI port, but the CDCLK frequency is decreasing (and not all pipes are
> being
> disabled). The current approach will not bump the voltage level up until
> after the
> port has already been enabled, which is too late.
> But we'll take care of that case separately.
>
> v2: Don't break the "must disable pipes case"
>
> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_cdclk.c | 15 +++++++++------
> drivers/gpu/drm/i915/display/intel_cdclk.h | 3 +++
> 2 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c
> b/drivers/gpu/drm/i915/display/intel_cdclk.c
> index 31aaa9780dfc..619529dba095 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> @@ -2600,7 +2600,6 @@ intel_set_cdclk_pre_plane_update(struct
> intel_atomic_state *state)
> intel_atomic_get_old_cdclk_state(state);
> const struct intel_cdclk_state *new_cdclk_state =
> intel_atomic_get_new_cdclk_state(state);
> - enum pipe pipe = new_cdclk_state->pipe;
>
> if (!intel_cdclk_changed(&old_cdclk_state->actual,
> &new_cdclk_state->actual))
> @@ -2609,11 +2608,12 @@ intel_set_cdclk_pre_plane_update(struct
> intel_atomic_state *state)
> if (IS_DG2(i915))
> intel_cdclk_pcode_pre_notify(state);
>
> - if (pipe == INVALID_PIPE ||
> + if (new_cdclk_state->disable_pipes ||
> old_cdclk_state->actual.cdclk <= new_cdclk_state->actual.cdclk) {
> drm_WARN_ON(&i915->drm, !new_cdclk_state-
> >base.changed);
>
> - intel_set_cdclk(i915, &new_cdclk_state->actual, pipe);
> + intel_set_cdclk(i915, &new_cdclk_state->actual,
> + new_cdclk_state->pipe);
> }
> }
>
> @@ -2632,7 +2632,6 @@ intel_set_cdclk_post_plane_update(struct
> intel_atomic_state *state)
> intel_atomic_get_old_cdclk_state(state);
> const struct intel_cdclk_state *new_cdclk_state =
> intel_atomic_get_new_cdclk_state(state);
> - enum pipe pipe = new_cdclk_state->pipe;
>
> if (!intel_cdclk_changed(&old_cdclk_state->actual,
> &new_cdclk_state->actual))
> @@ -2641,11 +2640,12 @@ intel_set_cdclk_post_plane_update(struct
> intel_atomic_state *state)
> if (IS_DG2(i915))
> intel_cdclk_pcode_post_notify(state);
>
> - if (pipe != INVALID_PIPE &&
> + if (!new_cdclk_state->disable_pipes &&
> old_cdclk_state->actual.cdclk > new_cdclk_state->actual.cdclk) {
> drm_WARN_ON(&i915->drm, !new_cdclk_state-
> >base.changed);
>
> - intel_set_cdclk(i915, &new_cdclk_state->actual, pipe);
> + intel_set_cdclk(i915, &new_cdclk_state->actual,
> + new_cdclk_state->pipe);
> }
> }
>
> @@ -3124,6 +3124,7 @@ static struct intel_global_state
> *intel_cdclk_duplicate_state(struct intel_globa
> return NULL;
>
> cdclk_state->pipe = INVALID_PIPE;
> + cdclk_state->disable_pipes = false;
>
> return &cdclk_state->base;
> }
> @@ -3316,6 +3317,8 @@ int intel_modeset_calc_cdclk(struct
> intel_atomic_state *state)
> if (ret)
> return ret;
>
> + new_cdclk_state->disable_pipes = true;
> +
> drm_dbg_kms(&dev_priv->drm,
> "Modeset required for cdclk change\n");
> }
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.h
> b/drivers/gpu/drm/i915/display/intel_cdclk.h
> index bc8f86e292d8..2843fc091086 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.h
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.h
> @@ -53,6 +53,9 @@ struct intel_cdclk_state {
>
> /* bitmask of active pipes */
> u8 active_pipes;
> +
> + /* update cdclk with pipes disabled */
> + bool disable_pipes;
> };
>
> int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state);
> --
> 2.43.2
