[Intel-gfx] [PATCH v3 09/16] drm/i915/gen9: Drop re-allocation of DDB at atomic commit (v2)

Lyude Paul cpaul at redhat.com
Fri May 6 18:42:46 UTC 2016


On Fri, 2016-05-06 at 14:12 -0400, Lyude Paul wrote:
> On Thu, 2016-04-21 at 16:17 -0700, Matt Roper wrote:
> > 
> > Now that we're properly pre-allocating the DDB during the atomic check
> > phase and we trust that the allocation is appropriate, let's actually
> > use the allocation computed and not duplicate that work during the
> > commit phase.
> > 
> > v2:
> >  - Significant rebasing now that we can use cached data rates and
> >    minimum block allocations to avoid grabbing additional plane states.
> > 
> > Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> > Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_display.c |  14 +--
> >  drivers/gpu/drm/i915/intel_pm.c      | 224 +++++++++++---------------------
> > --
> > -
> >  2 files changed, 67 insertions(+), 171 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c
> > b/drivers/gpu/drm/i915/intel_display.c
> > index c970e3e..80d8f77 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -13599,6 +13599,7 @@ static int intel_atomic_commit(struct drm_device
> > *dev,
> >  
> >  	drm_atomic_helper_swap_state(dev, state);
> >  	dev_priv->wm.config = intel_state->wm_config;
> > +	dev_priv->wm.skl_results.ddb = intel_state->ddb;
> >  	intel_shared_dpll_commit(state);
> >  
> >  	if (intel_state->modeset) {
> > @@ -13716,19 +13717,6 @@ static int intel_atomic_commit(struct drm_device
> > *dev,
> >  		intel_modeset_verify_crtc(crtc, old_crtc_state, crtc-
> > >state);
> >  	}
> >  
> > -	/*
> > -	 * Temporary sanity check: make sure our pre-computed DDB matches
> > the
> > -	 * one we actually wind up programming.
> > -	 *
> > -	 * Not a great place to put this, but the easiest place we have
> > access
> > -	 * to both the pre-computed and final DDB's; we'll be removing this
> > -	 * check in the next patch anyway.
> > -	 */
> > -	WARN(IS_GEN9(dev) &&
> > -	     memcmp(&intel_state->ddb, &dev_priv->wm.skl_results.ddb,
> > -		    sizeof(intel_state->ddb)),
> > -	     "Pre-computed DDB does not match final DDB!\n");
> > -
> >  	if (intel_state->modeset)
> >  		intel_display_power_put(dev_priv, POWER_DOMAIN_MODESET);
> >  
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c
> > b/drivers/gpu/drm/i915/intel_pm.c
> > index fca44f8..f28fd36 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -2849,7 +2849,6 @@ skl_wm_plane_id(const struct intel_plane *plane)
> >  static void
> >  skl_ddb_get_pipe_allocation_limits(struct drm_device *dev,
> >  				   const struct intel_crtc_state *cstate,
> > -				   struct intel_wm_config *config,
> >  				   struct skl_ddb_entry *alloc, /* out */
> >  				   int *num_active /* out */)
> >  {
> > @@ -2857,24 +2856,22 @@ skl_ddb_get_pipe_allocation_limits(struct drm_device
> > *dev,
> >  	struct intel_atomic_state *intel_state =
> > to_intel_atomic_state(state);
> >  	struct drm_i915_private *dev_priv = to_i915(dev);
> >  	struct drm_crtc *for_crtc = cstate->base.crtc;
> > -	struct drm_crtc *crtc;
> >  	unsigned int pipe_size, ddb_size;
> >  	int nth_active_pipe;
> >  	int pipe = to_intel_crtc(for_crtc)->pipe;
> >  
> > -	if (intel_state && intel_state->active_pipe_changes)
> > -		*num_active = hweight32(intel_state->active_crtcs);
> > -	else if (intel_state)
> > -		*num_active = hweight32(dev_priv->active_crtcs);
> > -	else
> > -		*num_active = config->num_pipes_active;
> > -
> > -	if (!cstate->base.active) {
> > +	if (WARN_ON(!state) || !cstate->base.active) {
> >  		alloc->start = 0;
> >  		alloc->end = 0;
> > +		*num_active = hweight32(dev_priv->active_crtcs);
> >  		return;
> >  	}
> >  
> > +	if (intel_state->active_pipe_changes)
> > +		*num_active = hweight32(intel_state->active_crtcs);
> > +	else
> > +		*num_active = hweight32(dev_priv->active_crtcs);
> > +
> >  	if (IS_BROXTON(dev))
> >  		ddb_size = BXT_DDB_SIZE;
> >  	else
> > @@ -2883,50 +2880,23 @@ skl_ddb_get_pipe_allocation_limits(struct drm_device
> > *dev,
> >  	ddb_size -= 4; /* 4 blocks for bypass path allocation */
> >  
> >  	/*
> > -	 * FIXME: At the moment we may be called on either in-flight or
> > fully
> > -	 * committed cstate's.  Once we fully move DDB allocation in the
> > check
> > -	 * phase, we'll only be called on in-flight states and the 'else'
> > -	 * branch here will go away.
> > -	 *
> > -	 * The 'else' branch is slightly racy here, but it was racy to
> > begin
> > -	 * with; since it's going away soon, no effort is made to address
> > that.
> > +	 * If the state doesn't change the active CRTC's, then there's
> > +	 * no need to recalculate; the existing pipe allocation limits
> > +	 * should remain unchanged.  Note that we're safe from racing
> > +	 * commits since any racing commit that changes the active CRTC
> > +	 * list would need to grab _all_ crtc locks, including the one
> > +	 * we currently hold.
> >  	 */
> > -	if (state) {
> > -		/*
> > -		 * If the state doesn't change the active CRTC's, then
> > there's
> > -		 * no need to recalculate; the existing pipe allocation
> > limits
> > -		 * should remain unchanged.  Note that we're safe from
> > racing
> > -		 * commits since any racing commit that changes the active
> > CRTC
> > -		 * list would need to grab _all_ crtc locks, including the
> > one
> > -		 * we currently hold.
> > -		 */
> > -		if (!intel_state->active_pipe_changes) {
> > -			*alloc = dev_priv->wm.skl_hw.ddb.pipe[pipe];
> > -			return;
> > -		}
> > -
> > -		nth_active_pipe = hweight32(intel_state->active_crtcs &
> > -					    (drm_crtc_mask(for_crtc) - 1));
> > -		pipe_size = ddb_size / hweight32(intel_state-
> > >active_crtcs);
> > -		alloc->start = nth_active_pipe * ddb_size / *num_active;
> > -		alloc->end = alloc->start + pipe_size;
> > -	} else {
> > -		nth_active_pipe = 0;
> > -		for_each_crtc(dev, crtc) {
> > -			if (!to_intel_crtc(crtc)->active)
> > -				continue;
> > -
> > -			if (crtc == for_crtc)
> > -				break;
> > -
> > -			nth_active_pipe++;
> > -		}
> > -
> > -		pipe_size = ddb_size / config->num_pipes_active;
> > -		alloc->start = nth_active_pipe * ddb_size /
> > -			config->num_pipes_active;
> > -		alloc->end = alloc->start + pipe_size;
> > +	if (!intel_state->active_pipe_changes) {
> > +		*alloc = dev_priv->wm.skl_hw.ddb.pipe[pipe];
> So I finally figured out what's causing all of the valid wm calculations to
> get
> rejected, leading to blank screens etc. etc. The problem is this line right
> here
> where we assign *alloc, we never actually set dev_priv-
> >wm.skl_hw.ddb.pipe[pipe] 
> to a value anywhere so we end up having bogus ddb entry sizes. If you change
> it
> to something like:
> 
> 		*alloc = dev_priv->wm.skl_hw.ddb.plane[pipe][intel_crtc->plane];
Whoops, I stand corrected on this, since this seems to cause a few issues with
VT switching. We actually want something like this:

		if (!intel_state->active_pipe_changes &&
		    dev_priv->wm.skl_hw.ddb.pipe[pipe].end != 0) {
			*alloc = dev_priv->wm.skl_hw.ddb.pipe[pipe];
			return;
		}

> 
> We get the right values and everything starts working as expected. BTW: Things
> seem to be pretty stable with this patchset after this fix, haven't tried it
> on
> any other platforms then skl yet though so I'll let you know if I run into any
> more problems.
> 
> > 
> > +		return;
> >  	}
> > +
> > +	nth_active_pipe = hweight32(intel_state->active_crtcs &
> > +				    (drm_crtc_mask(for_crtc) - 1));
> > +	pipe_size = ddb_size / hweight32(intel_state->active_crtcs);
> > +	alloc->start = nth_active_pipe * ddb_size / *num_active;
> > +	alloc->end = alloc->start + pipe_size;
> >  }
> >  
> >  static unsigned int skl_cursor_allocation(int num_active)
> > @@ -3025,62 +2995,33 @@ skl_get_total_relative_data_rate(struct
> > intel_crtc_state *intel_cstate)
> >  	struct drm_crtc *crtc = cstate->crtc;
> >  	struct drm_device *dev = crtc->dev;
> >  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> > +	const struct drm_plane *plane;
> >  	const struct intel_plane *intel_plane;
> > +	struct drm_plane_state *pstate;
> >  	unsigned int rate, total_data_rate = 0;
> >  	int id;
> > +	int i;
> > +
> > +	if (WARN_ON(!state))
> > +		return 0;
> >  
> >  	/* Calculate and cache data rate for each plane */
> > -	/*
> > -	 * FIXME: At the moment this function can be called on either an
> > -	 * in-flight or a committed state object.  If it's in-flight then
> > we
> > -	 * only want to re-calculate the plane data rate for planes that
> > are
> > -	 * part of the transaction (i.e., we don't want to grab any
> > additional
> > -	 * plane states if we don't have to).  If we're operating on
> > committed
> > -	 * state, we'll just go ahead and recalculate the plane data rate
> > for
> > -	 * all planes.
> > -	 *
> > -	 * Once we finish moving our DDB allocation to the atomic check
> > phase,
> > -	 * we'll only be calling this function on in-flight state objects,
> > so
> > -	 * the 'else' branch here will go away.
> > -	 */
> > -	if (state) {
> > -		struct drm_plane *plane;
> > -		struct drm_plane_state *pstate;
> > -		int i;
> > -
> > -		for_each_plane_in_state(state, plane, pstate, i) {
> > -			intel_plane = to_intel_plane(plane);
> > -			id = skl_wm_plane_id(intel_plane);
> > -
> > -			if (intel_plane->pipe != intel_crtc->pipe)
> > -				continue;
> > -
> > -			/* packed/uv */
> > -			rate = skl_plane_relative_data_rate(intel_cstate,
> > -							    pstate, 0);
> > -			intel_cstate->wm.skl.plane_data_rate[id] = rate;
> > -
> > -			/* y-plane */
> > -			rate = skl_plane_relative_data_rate(intel_cstate,
> > -							    pstate, 1);
> > -			intel_cstate->wm.skl.plane_y_data_rate[id] = rate;
> > -		}
> > -	} else {
> > -		for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane)
> > {
> > -			const struct drm_plane_state *pstate =
> > -				intel_plane->base.state;
> > -			int id = skl_wm_plane_id(intel_plane);
> > +	for_each_plane_in_state(state, plane, pstate, i) {
> > +		id = skl_wm_plane_id(to_intel_plane(plane));
> > +		intel_plane = to_intel_plane(plane);
> >  
> > -			/* packed/uv */
> > -			rate = skl_plane_relative_data_rate(intel_cstate,
> > -							    pstate, 0);
> > -			intel_cstate->wm.skl.plane_data_rate[id] = rate;
> > +		if (intel_plane->pipe != intel_crtc->pipe)
> > +			continue;
> >  
> > -			/* y-plane */
> > -			rate = skl_plane_relative_data_rate(intel_cstate,
> > -							    pstate, 1);
> > -			intel_cstate->wm.skl.plane_y_data_rate[id] = rate;
> > -		}
> > +		/* packed/uv */
> > +		rate = skl_plane_relative_data_rate(intel_cstate,
> > +						    pstate, 0);
> > +		intel_cstate->wm.skl.plane_data_rate[id] = rate;
> > +
> > +		/* y-plane */
> > +		rate = skl_plane_relative_data_rate(intel_cstate,
> > +						    pstate, 1);
> > +		intel_cstate->wm.skl.plane_y_data_rate[id] = rate;
> >  	}
> >  
> >  	/* Calculate CRTC's total data rate from cached values */
> > @@ -3104,8 +3045,6 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
> >  	struct drm_atomic_state *state = cstate->base.state;
> >  	struct drm_crtc *crtc = cstate->base.crtc;
> >  	struct drm_device *dev = crtc->dev;
> > -	struct drm_i915_private *dev_priv = to_i915(dev);
> > -	struct intel_wm_config *config = &dev_priv->wm.config;
> >  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> >  	struct intel_plane *intel_plane;
> >  	struct drm_plane *plane;
> > @@ -3119,6 +3058,9 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
> >  	int num_active;
> >  	int id, i;
> >  
> > +	if (WARN_ON(!state))
> > +		return 0;
> > +
> >  	if (!cstate->base.active) {
> >  		ddb->pipe[pipe].start = ddb->pipe[pipe].end = 0;
> >  		memset(ddb->plane[pipe], 0, sizeof(ddb->plane[pipe]));
> > @@ -3126,8 +3068,7 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
> >  		return 0;
> >  	}
> >  
> > -	skl_ddb_get_pipe_allocation_limits(dev, cstate, config, alloc,
> > -					   &num_active);
> > +	skl_ddb_get_pipe_allocation_limits(dev, cstate, alloc,
> > &num_active);
> >  	alloc_size = skl_ddb_entry_size(alloc);
> >  	if (alloc_size == 0) {
> >  		memset(ddb->plane[pipe], 0, sizeof(ddb->plane[pipe]));
> > @@ -3139,53 +3080,31 @@ skl_allocate_pipe_ddb(struct intel_crtc_state
> > *cstate,
> >  	ddb->plane[pipe][PLANE_CURSOR].end = alloc->end;
> >  
> >  	alloc_size -= cursor_blocks;
> > -	alloc->end -= cursor_blocks;
> >  
> >  	/* 1. Allocate the mininum required blocks for each active plane */
> > -	/*
> > -	 * TODO: Remove support for already-committed state once we
> > -	 * only allocate DDB on in-flight states.
> > -	 */
> > -	if (state) {
> > -		for_each_plane_in_state(state, plane, pstate, i) {
> > -			intel_plane = to_intel_plane(plane);
> > -			id = skl_wm_plane_id(intel_plane);
> > -
> > -			if (intel_plane->pipe != pipe)
> > -				continue;
> > -
> > -			if (!to_intel_plane_state(pstate)->visible) {
> > -				minimum[id] = 0;
> > -				y_minimum[id] = 0;
> > -				continue;
> > -			}
> > -			if (plane->type == DRM_PLANE_TYPE_CURSOR) {
> > -				minimum[id] = 0;
> > -				y_minimum[id] = 0;
> > -				continue;
> > -			}
> > -
> > -			minimum[id] = 8;
> > -			if (pstate->fb->pixel_format == DRM_FORMAT_NV12)
> > -				y_minimum[id] = 8;
> > -			else
> > -				y_minimum[id] = 0;
> > -		}
> > -	} else {
> > -		for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane)
> > {
> > -			struct drm_plane *plane = &intel_plane->base;
> > -			struct drm_framebuffer *fb = plane->state->fb;
> > -			int id = skl_wm_plane_id(intel_plane);
> > -
> > -			if (!to_intel_plane_state(plane->state)->visible)
> > -				continue;
> > +	for_each_plane_in_state(state, plane, pstate, i) {
> > +		intel_plane = to_intel_plane(plane);
> > +		id = skl_wm_plane_id(intel_plane);
> >  
> > -			if (plane->type == DRM_PLANE_TYPE_CURSOR)
> > -				continue;
> > +		if (intel_plane->pipe != pipe)
> > +			continue;
> >  
> > -			minimum[id] = 8;
> > -			y_minimum[id] = (fb->pixel_format ==
> > DRM_FORMAT_NV12)
> > ? 8 : 0;
> > +		if (!to_intel_plane_state(pstate)->visible) {
> > +			minimum[id] = 0;
> > +			y_minimum[id] = 0;
> > +			continue;
> > +		}
> > +		if (plane->type == DRM_PLANE_TYPE_CURSOR) {
> > +			minimum[id] = 0;
> > +			y_minimum[id] = 0;
> > +			continue;
> >  		}
> > +
> > +		minimum[id] = 8;
> > +		if (pstate->fb->pixel_format == DRM_FORMAT_NV12)
> > +			y_minimum[id] = 8;
> > +		else
> > +			y_minimum[id] = 0;
> >  	}
> >  
> >  	for (i = 0; i < PLANE_CURSOR; i++) {
> > @@ -3736,7 +3655,6 @@ static bool skl_update_pipe_wm(struct drm_crtc *crtc,
> >  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> >  	struct intel_crtc_state *cstate = to_intel_crtc_state(crtc->state);
> >  
> > -	WARN_ON(skl_allocate_pipe_ddb(cstate, ddb) != 0);
> >  	skl_build_pipe_wm(cstate, ddb, pipe_wm);
> >  
> >  	if (!memcmp(&intel_crtc->wm.active.skl, pipe_wm, sizeof(*pipe_wm)))
> > @@ -3800,16 +3718,6 @@ static void skl_clear_wm(struct skl_wm_values
> > *watermarks, enum pipe pipe)
> >  	memset(watermarks->plane_trans[pipe],
> >  	       0, sizeof(uint32_t) * I915_MAX_PLANES);
> >  	watermarks->plane_trans[pipe][PLANE_CURSOR] = 0;
> > -
> > -	/* Clear ddb entries for pipe */
> > -	memset(&watermarks->ddb.pipe[pipe], 0, sizeof(struct
> > skl_ddb_entry));
> > -	memset(&watermarks->ddb.plane[pipe], 0,
> > -	       sizeof(struct skl_ddb_entry) * I915_MAX_PLANES);
> > -	memset(&watermarks->ddb.y_plane[pipe], 0,
> > -	       sizeof(struct skl_ddb_entry) * I915_MAX_PLANES);
> > -	memset(&watermarks->ddb.plane[pipe][PLANE_CURSOR], 0,
> > -	       sizeof(struct skl_ddb_entry));
> > -
> >  }
> >  
> >  static int


More information about the Intel-gfx mailing list