Re: [PATCH 11/15] drm/i915: Add NV12 to primary plane programming.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Sep 09, 2015 at 02:30:58AM +0300, Konduru, Chandra wrote:
> > > > > +		if (fb->pixel_format == DRM_FORMAT_NV12) {
> > > > > +			int height_in_mem = (fb->offsets[1]/fb->pitches[0]);
> > > > > +			/*
> > > > > +			 * If UV starts from middle of a page, then UV start
> > > > should
> > > > > +			 * be programmed to beginning of that page. And offset
> > > > into that
> > > > > +			 * page to be programmed into y-offset
> > > > > +			 */
> > > > > +			tile_row_adjustment = height_in_mem % tile_height;
> > > > > +			aux_dist = fb->pitches[0] * (height_in_mem -
> > > > tile_row_adjustment);
> > > > > +			aux_x_offset = DIV_ROUND_UP(x, 2);
> > > > > +			aux_y_offset = DIV_ROUND_UP(y, 2) +
> > > > tile_row_adjustment;
> > > > > +			/* For tile-Yf, uv-subplane tile width is 2x of Y-subplane
> > > > */
> > > > > +			aux_stride = fb->modifier[0] ==
> > > > I915_FORMAT_MOD_Yf_TILED ?
> > > > > +				stride / 2 : stride;
> > > >
> > > > The 2x part was rather well hidden in the spec. How do we deal with
> > > > cases when the Y stride is an odd number of tiles?
> > >
> > > It should be a round up division to take care of that scenario.
> > 
> > That would stil lresult in a corrupted picture I think. So I was
> > thinking that we should just refuse to create NCV12 framebuffers with a
> > poorly aligned stride.
> > 
> I added a check in intel_framebuffer_init() which should catch them:
>         if (mode_cmd->pitches[0] != mode_cmd->pitches[1]) {
>             DRM_DEBUG("y and uv subplanes have different pitches\n");
>             return -EINVAL;
>         }

That won't catch the case I'm worried about. We would also need to make
sure pitches[1] is aligned to the UV tile width.

-- 
Ville Syrjälä
Intel OTC
---------------------------------------------------------------------
Intel Finland Oy
Registered Address: PL 281, 00181 Helsinki 
Business Identity Code: 0357606 - 4 
Domiciled in Helsinki 

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.

_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx




[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux