[PATCH 5/5] drm/i915: Implement vblank synchronized MBUS join changes

Lisovskiy, Stanislav stanislav.lisovskiy at intel.com
Mon Mar 25 08:59:58 UTC 2024


On Fri, Mar 22, 2024 at 08:06:46PM +0200, Ville Syrjälä wrote:
> On Fri, Mar 22, 2024 at 01:40:46PM +0200, 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.
> > 
> > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.c |   6 +-
> >  drivers/gpu/drm/i915/display/skl_watermark.c | 108 +++++++++++++++----
> >  drivers/gpu/drm/i915/display/skl_watermark.h |   2 +
> >  3 files changed, 94 insertions(+), 22 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > index b88f214e111ae..d5351f6fa2eb4 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -6895,6 +6895,8 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
> >  		intel_pre_update_crtc(state, crtc);
> >  	}
> >  
> > +	intel_dbuf_mbus_pre_ddb_update(state);
> > +
> >  	while (update_pipes) {
> >  		for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
> >  						    new_crtc_state, i) {
> > @@ -6925,6 +6927,8 @@ static void skl_commit_modeset_enables(struct intel_atomic_state *state)
> >  		}
> >  	}
> >  
> > +	intel_dbuf_mbus_post_ddb_update(state);
> > +
> >  	update_pipes = modeset_pipes;
> >  
> >  	/*
> > @@ -7169,9 +7173,7 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
> >  	}
> >  
> >  	intel_encoders_update_prepare(state);
> > -
> >  	intel_dbuf_pre_plane_update(state);
> > -	intel_mbus_dbox_update(state);
> >  
> >  	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
> >  		if (new_crtc_state->do_async_flip)
> > diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
> > index 7eb78e0c8c8e3..eee13b57d4830 100644
> > --- a/drivers/gpu/drm/i915/display/skl_watermark.c
> > +++ b/drivers/gpu/drm/i915/display/skl_watermark.c
> > @@ -4,6 +4,7 @@
> >   */
> >  
> >  #include <drm/drm_blend.h>
> > +#include <drm/drm_print.h>
> >  
> >  #include "i915_drv.h"
> >  #include "i915_fixed.h"
> > @@ -2636,13 +2637,6 @@ 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_late(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,
> > @@ -3594,30 +3588,57 @@ static void intel_dbuf_mdclk_min_tracker_update(struct intel_atomic_state *state
> >  					    new_dbuf_state->joined_mbus);
> >  }
> >  
> > +static enum pipe intel_mbus_joined_pipe(struct intel_atomic_state *state,
> > +				        const struct intel_dbuf_state *dbuf_state)
> > +{
> > +	struct drm_i915_private *i915 = to_i915(state->base.dev);
> > +	enum pipe sync_pipe = ffs(dbuf_state->active_pipes) - 1;
> > +	struct intel_crtc_state *new_crtc_state;
> 
> const
> 
> > +	struct intel_crtc *crtc;
> > +
> > +	drm_WARN_ON(&i915->drm, !dbuf_state->joined_mbus);
> > +	drm_WARN_ON(&i915->drm, !is_power_of_2(dbuf_state->active_pipes));
> > +
> > +	crtc = intel_crtc_for_pipe(i915, sync_pipe);
> > +	new_crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
> > +
> > +	if (new_crtc_state && !intel_crtc_needs_modeset(new_crtc_state))
> > +		return sync_pipe;
> > +	else
> > +		return INVALID_PIPE;
> > +}
> > +
> >  /*
> >   * Configure MBUS_CTL and all DBUF_CTL_S of each slice to join_mbus state before
> >   * update the request state of all DBUS slices.
> >   */
> > -static void intel_dbuf_mbus_join_update(struct intel_atomic_state *state)
> > +static void intel_dbuf_mbus_ctl_update(struct intel_atomic_state *state,
> > +				       enum pipe sync_pipe)
> >  {
> >  	struct drm_i915_private *i915 = to_i915(state->base.dev);
> >  	u32 mbus_ctl;
> >  	const struct intel_dbuf_state *new_dbuf_state =
> >  		intel_atomic_get_new_dbuf_state(state);
> > +	u32 pipe_select;
> >  
> >  	if (!HAS_MBUS_JOINING(i915))
> >  		return;
> >  
> > +	if (sync_pipe != INVALID_PIPE)
> > +		pipe_select = MBUS_JOIN_PIPE_SELECT(sync_pipe);
> > +	else
> > +		pipe_select = MBUS_JOIN_PIPE_SELECT_NONE;
> > +
> >  	/*
> >  	 * TODO: Implement vblank synchronized MBUS joining changes.
> >  	 * Must be properly coordinated with dbuf reprogramming.
> >  	 */
> >  	if (new_dbuf_state->joined_mbus)
> >  		mbus_ctl = MBUS_HASHING_MODE_1x4 | MBUS_JOIN |
> > -			MBUS_JOIN_PIPE_SELECT_NONE;
> > +			pipe_select;
> >  	else
> >  		mbus_ctl = MBUS_HASHING_MODE_2x2 |
> > -			MBUS_JOIN_PIPE_SELECT_NONE;
> > +			pipe_select;
> 
> The 'pipe_select' variable looks completely redundant.
> You can just do
> if (sync_pipe != INVALID_PIPE)
> 	mbus_ctl |= ...
> else
> 	mbus_ctl |= ...
> directly here.
> 
> >  
> >  	intel_de_rmw(i915, MBUS_CTL,
> >  		     MBUS_HASHING_MODE_MASK | MBUS_JOIN |
> > @@ -3632,6 +3653,42 @@ void intel_dbuf_pre_plane_update(struct intel_atomic_state *state)
> >  	const struct intel_dbuf_state *old_dbuf_state =
> >  		intel_atomic_get_old_dbuf_state(state);
> >  
> > +	if (!new_dbuf_state ||
> > +	    (new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices))
> 
> redundant parens.
> 
> > +		return;
> > +
> > +	WARN_ON(!new_dbuf_state->base.changed);
> > +
> > +	gen9_dbuf_slices_update(i915,
> > +				old_dbuf_state->enabled_slices |
> > +				new_dbuf_state->enabled_slices);
> > +}
> > +
> > +void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
> > +{
> > +	struct drm_i915_private *i915 = to_i915(state->base.dev);
> > +	const struct intel_dbuf_state *new_dbuf_state =
> > +		intel_atomic_get_new_dbuf_state(state);
> > +	const struct intel_dbuf_state *old_dbuf_state =
> > +		intel_atomic_get_old_dbuf_state(state);
> > +
> > +	if (!new_dbuf_state ||
> > +	    (new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices))
> 
> ditto
> 
> > +		return;
> > +
> > +	WARN_ON(!new_dbuf_state->base.changed);
> > +
> > +	gen9_dbuf_slices_update(i915,
> > +				new_dbuf_state->enabled_slices);
> > +}
> > +
> > +void intel_dbuf_mbus_pre_ddb_update(struct intel_atomic_state *state)
> > +{
> > +	const struct intel_dbuf_state *new_dbuf_state =
> > +		intel_atomic_get_new_dbuf_state(state);
> > +	const struct intel_dbuf_state *old_dbuf_state =
> > +		intel_atomic_get_old_dbuf_state(state);
> > +
> >  	if (!new_dbuf_state ||
> >  	    (new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices &&
> >  	     new_dbuf_state->joined_mbus == old_dbuf_state->joined_mbus))
> > @@ -3640,16 +3697,15 @@ void intel_dbuf_pre_plane_update(struct intel_atomic_state *state)
> >  	WARN_ON(!new_dbuf_state->base.changed);
> >  
> >  	if (!old_dbuf_state->joined_mbus && new_dbuf_state->joined_mbus) {
> > -		intel_dbuf_mbus_join_update(state);
> > +		enum pipe sync_pipe = intel_mbus_joined_pipe(state, new_dbuf_state);
> > +
> > +		intel_dbuf_mbus_ctl_update(state, sync_pipe);
> > +		intel_mbus_dbox_update(state);
> >  		intel_dbuf_mdclk_min_tracker_update(state);
> >  	}
> > -
> > -	gen9_dbuf_slices_update(i915,
> > -				old_dbuf_state->enabled_slices |
> > -				new_dbuf_state->enabled_slices);
> >  }
> >  
> > -void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
> > +void intel_dbuf_mbus_post_ddb_update(struct intel_atomic_state *state)
> >  {
> >  	struct drm_i915_private *i915 = to_i915(state->base.dev);
> >  	const struct intel_dbuf_state *new_dbuf_state =
> > @@ -3657,6 +3713,12 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
> >  	const struct intel_dbuf_state *old_dbuf_state =
> >  		intel_atomic_get_old_dbuf_state(state);
> >  
> > +	if (new_dbuf_state && old_dbuf_state &&
> > +	    new_dbuf_state->joined_mbus == old_dbuf_state->joined_mbus) {
> > +		intel_dbuf_mdclk_min_tracker_update(state);
> > +		intel_mbus_dbox_update(state);
> > +	}
> 
> I still think should go into one of the new ddb hooks.
> I think we want to program these before the new planes
> get enabled. So I'd probably stuff this into the post ddb
> hook.

I almost got confused myself, because I was really sure I've done this.
Checked the code - it is exactly in intel_dbuf_mbus_post_ddb_update.
If you check above you will see 

> > -void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
> > +void intel_dbuf_mbus_post_ddb_update(struct intel_atomic_state *state)

But was good one, already thought I messed up the commit or smth.

> 
> > +
> >  	if (!new_dbuf_state ||
> >  	    (new_dbuf_state->enabled_slices == old_dbuf_state->enabled_slices &&
> >  	     new_dbuf_state->joined_mbus == old_dbuf_state->joined_mbus))
> > @@ -3665,12 +3727,18 @@ void intel_dbuf_post_plane_update(struct intel_atomic_state *state)
> >  	WARN_ON(!new_dbuf_state->base.changed);
> >  
> >  	if (old_dbuf_state->joined_mbus && !new_dbuf_state->joined_mbus) {
> > -		intel_dbuf_mbus_join_update(state);
> > +		enum pipe sync_pipe = intel_mbus_joined_pipe(state, old_dbuf_state);
> > +
> >  		intel_dbuf_mdclk_min_tracker_update(state);
> > -	}
> > +		intel_mbus_dbox_update(state);
> > +		intel_dbuf_mbus_ctl_update(state, sync_pipe);
> >  
> > -	gen9_dbuf_slices_update(i915,
> > -				new_dbuf_state->enabled_slices);
> > +		if (sync_pipe != INVALID_PIPE) {
> > +			struct intel_crtc *crtc = intel_crtc_for_pipe(i915, sync_pipe);
> > +
> > +			intel_crtc_wait_for_next_vblank(crtc);
> > +		}
> > +	}
> >  }
> >  
> >  static bool xelpdp_is_only_pipe_per_dbuf_bank(enum pipe pipe, u8 active_pipes)
> > diff --git a/drivers/gpu/drm/i915/display/skl_watermark.h b/drivers/gpu/drm/i915/display/skl_watermark.h
> > index 3a90741cab06a..f6d38b41e3a6c 100644
> > --- a/drivers/gpu/drm/i915/display/skl_watermark.h
> > +++ b/drivers/gpu/drm/i915/display/skl_watermark.h
> > @@ -77,6 +77,8 @@ int intel_dbuf_state_set_mdclk_cdclk_ratio(struct intel_atomic_state *state, u8
> >  void intel_dbuf_pre_plane_update(struct intel_atomic_state *state);
> >  void intel_dbuf_post_plane_update(struct intel_atomic_state *state);
> >  void intel_dbuf_mdclk_cdclk_ratio_update(struct drm_i915_private *i915, u8 ratio, bool joined_mbus);
> > +void intel_dbuf_mbus_pre_ddb_update(struct intel_atomic_state *state);
> > +void intel_dbuf_mbus_post_ddb_update(struct intel_atomic_state *state);
> >  void intel_mbus_dbox_update(struct intel_atomic_state *state);
> >  
> >  #endif /* __SKL_WATERMARK_H__ */
> > -- 
> > 2.37.3
> 
> -- 
> Ville Syrjälä
> Intel


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