Re: [Intel-gfx] [PATCH 14/23] drm/i915/intel_fb: Factor out convert_plane_offset_to_xy()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Mar 11, 2021 at 06:32:14PM +0200, Ville Syrjälä wrote:
> On Thu, Mar 11, 2021 at 12:17:27AM +0200, Imre Deak wrote:
> > Factor out to a new function the logic to convert the FB plane offset to
> > x/y and check the validity of x/y, with the goal to make
> > intel_fill_fb_info() more readable.
> > 
> > Signed-off-by: Imre Deak <imre.deak@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_fb.c | 70 +++++++++++++++----------
> >  1 file changed, 42 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_fb.c b/drivers/gpu/drm/i915/display/intel_fb.c
> > index b96849ec32df..806341c229f0 100644
> > --- a/drivers/gpu/drm/i915/display/intel_fb.c
> > +++ b/drivers/gpu/drm/i915/display/intel_fb.c
> > @@ -400,10 +400,10 @@ static int intel_fb_offset_to_xy(int *x, int *y,
> >  	return 0;
> >  }
> >  
> > -static int intel_fb_check_ccs_xy(struct drm_framebuffer *fb, int ccs_plane, int x, int y)
> > +static int intel_fb_check_ccs_xy(const struct drm_framebuffer *fb, int ccs_plane, int x, int y)
> >  {
> >  	struct drm_i915_private *i915 = to_i915(fb->dev);
> > -	struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
> > +	const struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
> >  	int main_plane;
> >  	int hsub, vsub;
> >  	int tile_width, tile_height;
> > @@ -520,6 +520,45 @@ static bool intel_plane_needs_remap(const struct intel_plane_state *plane_state)
> >  	return stride > max_stride;
> >  }
> >  
> > +static int convert_plane_offset_to_xy(const struct intel_framebuffer *fb, int color_plane,
> > +				      int plane_width, int *x, int *y)
> > +{
> > +	const struct drm_framebuffer *drm_fb = &fb->base;
> 
> Not a fan of these aliasing pointers. I know that the fb 
> stuff is a bit of a mess when it comes to the drm_ vs. intel_
> usage.
> 
> We've mostly cleaned up that stuff for plane/crtc/etc. by just
> avoiding the aliasing pointers and just using foo->base where
> appropriate. Not sure how that sort of approach would look in
> the end of fbs?

Anyways, apart from that annoyance this seems fine.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> 
> > +	struct drm_i915_gem_object *obj = intel_fb_obj(drm_fb);
> > +	int ret;
> > +
> > +	ret = intel_fb_offset_to_xy(x, y, drm_fb, color_plane);
> > +	if (ret) {
> > +		drm_dbg_kms(drm_fb->dev,
> > +			    "bad fb plane %d offset: 0x%x\n",
> > +			    color_plane, drm_fb->offsets[color_plane]);
> > +		return ret;
> > +	}
> > +
> > +	ret = intel_fb_check_ccs_xy(drm_fb, color_plane, *x, *y);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/*
> > +	 * The fence (if used) is aligned to the start of the object
> > +	 * so having the framebuffer wrap around across the edge of the
> > +	 * fenced region doesn't really work. We have no API to configure
> > +	 * the fence start offset within the object (nor could we probably
> > +	 * on gen2/3). So it's just easier if we just require that the
> > +	 * fb layout agrees with the fence layout. We already check that the
> > +	 * fb stride matches the fence stride elsewhere.
> > +	 */
> > +	if (color_plane == 0 && i915_gem_object_is_tiled(obj) &&
> > +	    (*x + plane_width) * drm_fb->format->cpp[color_plane] > drm_fb->pitches[color_plane]) {
> > +		drm_dbg_kms(drm_fb->dev,
> > +			    "bad fb plane %d offset: 0x%x\n",
> > +			    color_plane, drm_fb->offsets[color_plane]);
> > +		return -EINVAL;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >  /*
> >   * Setup the rotated view for an FB plane and return the size the GTT mapping
> >   * requires for this view.
> > @@ -611,35 +650,10 @@ int intel_fill_fb_info(struct drm_i915_private *i915, struct drm_framebuffer *fb
> >  		cpp = fb->format->cpp[i];
> >  		intel_fb_plane_dims(&width, &height, fb, i);
> >  
> > -		ret = intel_fb_offset_to_xy(&x, &y, fb, i);
> > -		if (ret) {
> > -			drm_dbg_kms(&i915->drm,
> > -				    "bad fb plane %d offset: 0x%x\n",
> > -				    i, fb->offsets[i]);
> > -			return ret;
> > -		}
> > -
> > -		ret = intel_fb_check_ccs_xy(fb, i, x, y);
> > +		ret = convert_plane_offset_to_xy(intel_fb, i, width, &x, &y);
> >  		if (ret)
> >  			return ret;
> >  
> > -		/*
> > -		 * The fence (if used) is aligned to the start of the object
> > -		 * so having the framebuffer wrap around across the edge of the
> > -		 * fenced region doesn't really work. We have no API to configure
> > -		 * the fence start offset within the object (nor could we probably
> > -		 * on gen2/3). So it's just easier if we just require that the
> > -		 * fb layout agrees with the fence layout. We already check that the
> > -		 * fb stride matches the fence stride elsewhere.
> > -		 */
> > -		if (i == 0 && i915_gem_object_is_tiled(obj) &&
> > -		    (x + width) * cpp > fb->pitches[i]) {
> > -			drm_dbg_kms(&i915->drm,
> > -				    "bad fb plane %d offset: 0x%x\n",
> > -				     i, fb->offsets[i]);
> > -			return -EINVAL;
> > -		}
> > -
> >  		/*
> >  		 * First pixel of the framebuffer from
> >  		 * the start of the normal gtt mapping.
> > -- 
> > 2.25.1
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Ville Syrjälä
> Intel
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel
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