Message-ID: <1476389242.2478.33.camel@intel.com>
Date:   Thu, 13 Oct 2016 17:07:22 -0300
From:   Paulo Zanoni <paulo.r.zanoni@...el.com>
To:     Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Lyude <cpaul@...hat.com>, intel-gfx@...ts.freedesktop.org
Cc:     David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel.vetter@...el.com>,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH v2 05/10] drm/i915/gen9: Get rid of
 redundant watermark values

Em Qui, 2016-10-13 às 17:04 -0300, Paulo Zanoni escreveu:
> Em Qui, 2016-10-13 às 15:39 +0200, Maarten Lankhorst escreveu:
> > 
> > Op 08-10-16 om 02:11 schreef Lyude:
> > > 
> > > 
> > > Now that we've make skl_wm_levels make a little more sense, we
> > > can
> > > remove all of the redundant wm information. Up until now we'd
> > > been
> > > storing two copies of all of the skl watermarks: one being the
> > > skl_pipe_wm structs, the other being the global wm struct in
> > > drm_i915_private containing the raw register values. This is
> > > confusing
> > > and problematic, since it means we're prone to accidentally
> > > letting
> > > the
> > > two copies go out of sync. So, get rid of all of the functions
> > > responsible for computing the register values and just use a
> > > single
> > > helper, skl_write_wm_level(), to convert and write the new
> > > watermarks on
> > > the fly.
> > > 
> > > Changes since v1:
> > > - Fixup skl_write_wm_level()
> > > - Fixup skl_wm_level_from_reg_val()
> > > - Don't forget to copy *active to intel_crtc->wm.active.skl
> > > 
> > > Signed-off-by: Lyude <cpaul@...hat.com>
> > > Reviewed-by: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com
> > > >
> > > Cc: Ville Syrjälä <ville.syrjala@...ux.intel.com>
> > > Cc: Paulo Zanoni <paulo.r.zanoni@...el.com>
> > > ---
> > >  drivers/gpu/drm/i915/i915_drv.h      |   2 -
> > >  drivers/gpu/drm/i915/intel_display.c |  14 ++-
> > >  drivers/gpu/drm/i915/intel_drv.h     |   6 +-
> > >  drivers/gpu/drm/i915/intel_pm.c      | 204 ++++++++++++---------
> > > --
> > > ------------
> > >  drivers/gpu/drm/i915/intel_sprite.c  |   8 +-
> > >  5 files changed, 90 insertions(+), 144 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > > b/drivers/gpu/drm/i915/i915_drv.h
> > > index 0287c93..76583b2 100644
> > > --- a/drivers/gpu/drm/i915/i915_drv.h
> > > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > > @@ -1644,8 +1644,6 @@ struct skl_ddb_allocation {
> > >  struct skl_wm_values {
> > >  	unsigned dirty_pipes;
> > >  	struct skl_ddb_allocation ddb;
> > > -	uint32_t plane[I915_MAX_PIPES][I915_MAX_PLANES][8];
> > > -	uint32_t plane_trans[I915_MAX_PIPES][I915_MAX_PLANES];
> > >  };
> > >  
> > >  struct skl_wm_level {
> > > diff --git a/drivers/gpu/drm/i915/intel_display.c
> > > b/drivers/gpu/drm/i915/intel_display.c
> > > index a71d05a..39400a0 100644
> > > --- a/drivers/gpu/drm/i915/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/intel_display.c
> > > @@ -3378,6 +3378,8 @@ static void
> > > skylake_update_primary_plane(struct drm_plane *plane,
> > >  	struct intel_crtc *intel_crtc =
> > > to_intel_crtc(crtc_state-
> > > > 
> > > > base.crtc);
> > >  	struct drm_framebuffer *fb = plane_state->base.fb;
> > >  	const struct skl_wm_values *wm = &dev_priv-
> > > > 
> > > > wm.skl_results;
> > > +	const struct skl_plane_wm *p_wm =
> > > +		&crtc_state->wm.skl.optimal.planes[0];
> > >  	int pipe = intel_crtc->pipe;
> > >  	u32 plane_ctl;
> > >  	unsigned int rotation = plane_state->base.rotation;
> > > @@ -3414,7 +3416,7 @@ static void
> > > skylake_update_primary_plane(struct drm_plane *plane,
> > >  	intel_crtc->adjusted_y = src_y;
> > >  
> > >  	if (wm->dirty_pipes & drm_crtc_mask(&intel_crtc->base))
> > > -		skl_write_plane_wm(intel_crtc, wm, 0);
> > > +		skl_write_plane_wm(intel_crtc, p_wm, &wm->ddb,
> > > 0);
> > >  
> > >  	I915_WRITE(PLANE_CTL(pipe, 0), plane_ctl);
> > >  	I915_WRITE(PLANE_OFFSET(pipe, 0), (src_y << 16) |
> > > src_x);
> > > @@ -3448,6 +3450,8 @@ static void
> > > skylake_disable_primary_plane(struct drm_plane *primary,
> > >  	struct drm_device *dev = crtc->dev;
> > >  	struct drm_i915_private *dev_priv = to_i915(dev);
> > >  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> > > +	struct intel_crtc_state *cstate =
> > > to_intel_crtc_state(crtc->state);
> > > +	const struct skl_plane_wm *p_wm = &cstate-
> > > > 
> > > > wm.skl.optimal.planes[0];
> > >  	int pipe = intel_crtc->pipe;
> > >  
> > >  	/*
> > > @@ -3455,7 +3459,8 @@ static void
> > > skylake_disable_primary_plane(struct drm_plane *primary,
> > >  	 * plane's visiblity isn't actually changing neither is
> > > its watermarks.
> > >  	 */
> > >  	if (!crtc->primary->state->visible)
> > > -		skl_write_plane_wm(intel_crtc, &dev_priv-
> > > > 
> > > > wm.skl_results, 0);
> > > +		skl_write_plane_wm(intel_crtc, p_wm,
> > > +				   &dev_priv-
> > > >wm.skl_results.ddb,
> > > 0);
> > >  
> > >  	I915_WRITE(PLANE_CTL(pipe, 0), 0);
> > >  	I915_WRITE(PLANE_SURF(pipe, 0), 0);
> > > @@ -10819,12 +10824,15 @@ static void i9xx_update_cursor(struct
> > > drm_crtc *crtc, u32 base,
> > >  	struct drm_device *dev = crtc->dev;
> > >  	struct drm_i915_private *dev_priv = to_i915(dev);
> > >  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> > > +	struct intel_crtc_state *cstate =
> > > to_intel_crtc_state(crtc->state);
> > >  	const struct skl_wm_values *wm = &dev_priv-
> > > > 
> > > > wm.skl_results;
> > > +	const struct skl_plane_wm *p_wm =
> > > +		&cstate->wm.skl.optimal.planes[PLANE_CURSOR];
> > >  	int pipe = intel_crtc->pipe;
> > >  	uint32_t cntl = 0;
> > >  
> > >  	if (INTEL_GEN(dev_priv) >= 9 && wm->dirty_pipes &
> > > drm_crtc_mask(crtc))
> > > -		skl_write_cursor_wm(intel_crtc, wm);
> > > +		skl_write_cursor_wm(intel_crtc, p_wm, &wm->ddb);
> > >  
> > >  	if (plane_state && plane_state->base.visible) {
> > >  		cntl = MCURSOR_GAMMA_ENABLE;
> > > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > > b/drivers/gpu/drm/i915/intel_drv.h
> > > index d684f4f..958dc72 100644
> > > --- a/drivers/gpu/drm/i915/intel_drv.h
> > > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > > @@ -1765,9 +1765,11 @@ bool skl_ddb_allocation_equals(const
> > > struct
> > > skl_ddb_allocation *old,
> > >  bool skl_ddb_allocation_overlaps(struct drm_atomic_state *state,
> > >  				 struct intel_crtc *intel_crtc);
> > >  void skl_write_cursor_wm(struct intel_crtc *intel_crtc,
> > > -			 const struct skl_wm_values *wm);
> > > +			 const struct skl_plane_wm *wm,
> > > +			 const struct skl_ddb_allocation *ddb);
> > >  void skl_write_plane_wm(struct intel_crtc *intel_crtc,
> > > -			const struct skl_wm_values *wm,
> > > +			const struct skl_plane_wm *wm,
> > > +			const struct skl_ddb_allocation *ddb,
> > >  			int plane);
> > >  uint32_t ilk_pipe_pixel_rate(const struct intel_crtc_state
> > > *pipe_config);
> > >  bool ilk_disable_lp_wm(struct drm_device *dev);
> > > diff --git a/drivers/gpu/drm/i915/intel_pm.c
> > > b/drivers/gpu/drm/i915/intel_pm.c
> > > index 5dbaf12..5cb537c 100644
> > > --- a/drivers/gpu/drm/i915/intel_pm.c
> > > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > > @@ -3000,6 +3000,8 @@ bool intel_can_enable_sagv(struct
> > > drm_atomic_state *state)
> > >  	struct drm_i915_private *dev_priv = to_i915(dev);
> > >  	struct intel_atomic_state *intel_state =
> > > to_intel_atomic_state(state);
> > >  	struct drm_crtc *crtc;
> > > +	struct intel_crtc_state *cstate;
> > > +	struct skl_plane_wm *wm;
> > >  	enum pipe pipe;
> > >  	int level, plane;
> > >  
> > > @@ -3020,18 +3022,21 @@ bool intel_can_enable_sagv(struct
> > > drm_atomic_state *state)
> > >  	/* Since we're now guaranteed to only have one active
> > > CRTC... */
> > >  	pipe = ffs(intel_state->active_crtcs) - 1;
> > >  	crtc = dev_priv->pipe_to_crtc_mapping[pipe];
> > > +	cstate = intel_atomic_get_crtc_state(state,
> > > to_intel_crtc(crtc));
> > Wrong cstate here, should be crtc->state since it's committed and
> > crtc_state is the old state.
> 
> Ah... How many instances of the "you're looking at the wrong state
> struct" have we spotted/fixed ever since the introduction of the
> atomic
> code? Can't we try to do something more human-proof in order to avoid
> these problems from happening again and again?
> 
> Like for example copying the old states to a specific structure like
> drm_atomic_state->old_states_which_you_probably_shouldn_be_using, and
> then setting the CRTC/connector/plane states in the drm_atomic_state
> struct to NULL so bugs will be much easier to spot?
> 
> Anyway, with this problem fixed, feel free to add:
> Reviewed-by: Paulo Zanoni <paulo.r.zanoni@...el.com>

Oh, I forgot to mention: this patch has a conflict with my
"unconditionally apply the memory workaround" patch, so we may need to
decide which one gets merged first. Of course I'd suggest my patch to
be merged first since I want it to land in stable, but I'm always
biased towards my patches. If you agree, I can even volunteer myself to
solve the conflicts of this patch later when applying.

> 
> > 
> > 
> > ~Maarten
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