On Tue, Mar 26, 2024 at 06:42:09PM -0300, Gustavo Sousa wrote:
> Quoting Ville Syrjala (2024-03-26 17:31:26-03:00)
> >From: Ville Syrjälä <ville.syrj...@linux.intel.com>
> >
> >Currently we always reprogram CDCLK from the
> >intel_set_cdclk_post_plane_update() when using squahs/crawl.
>
> Hm... I'm not following this sentence. Looks like cdclk_state->pipe will
> be INVALID_PIPE unless it is a cd2x update, right?
>
> Did you mean intel_set_cdclk_pre_plane_update() above? That would make
> sense, because it seems we would be doing the update there even when
> decreasing the cdclk because of the condition pipe == INVALID_PIPE.
Yeah, apparently copy pasted in the wrong function name here.
>
> --
> Gustavo Sousa
>
> >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.
> >
> >So let us only consider the relationship of the old and
> >new CDCLK frequencies when determining where to do
> >the reprogramming, regarless of whether all pipes might
> >be off or not at the time.
> >
> >If the CDCLK freqiency remains unchanges we may still have to
> >do the reprogramming to change the voltage_level. Currently
> >we do that from intel_set_cdclk_pre_plane_update() which
> >probably is the right choice most of the time. The only
> >counterexample is when the voltage_level needs to increase
> >due to a DDI port, but the CDCLK frequency is decreasing.
> >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.
> >
> >Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
> >---
> > drivers/gpu/drm/i915/display/intel_cdclk.c | 14 ++++++--------
> > 1 file changed, 6 insertions(+), 8 deletions(-)
> >
> >diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c
> >b/drivers/gpu/drm/i915/display/intel_cdclk.c
> >index 31aaa9780dfc..49e2f09a796a 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 +2608,11 @@ 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 ||
> >- old_cdclk_state->actual.cdclk <= new_cdclk_state->actual.cdclk)
> >{
> >+ if (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 +2631,6 @@ 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 +2639,11 @@ 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 &&
> >- old_cdclk_state->actual.cdclk > new_cdclk_state->actual.cdclk) {
> >+ if (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);
> > }
> > }
> >
> >--
> >2.43.2
> >
--
Ville Syrjälä
Intel
