[Intel-gfx] [PATCH 06/11] drm/i915: Check the framebuffer offset

[Ville Syrjälä]

On Wed, Oct 31, 2012 at 01:26:12PM -0700, Jesse Barnes wrote:
> On Wed, 31 Oct 2012 17:50:19 +0200
> ville.syrjala at linux.intel.com wrote:
> 
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > The current code can't deal with framebuffers with an offset. Return an
> > error when trying to create such a framebuffer until the rest of the
> > code is fixed to handle them.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > ---
> > 
> > I had an earlier version that actually added the handling for the offsets,
> > but as I still haven't managed to write test cases for that, I decided
> > that just refusing any offset is a good enough solution for now.
> > 
> >  drivers/gpu/drm/i915/intel_display.c |    4 ++++
> >  1 files changed, 4 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index f431f2a..a3496f5 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -8276,6 +8276,10 @@ int intel_framebuffer_init(struct drm_device *dev,
> >  		return -EINVAL;
> >  	}
> >  
> > +	/* FIXME need to adjust LINOFF/TILEOFF accordingly. */
> > +	if (mode_cmd->offsets[0] != 0)
> > +		return -EINVAL;
> > +
> >  	ret = drm_framebuffer_init(dev, &intel_fb->base, &intel_fb_funcs);
> >  	if (ret) {
> >  		DRM_ERROR("framebuffer init failed %d\n", ret);
> 
> Userspace doesn't use this today at all even in the panning case?

If it does, then the user is going to be upset when nothing happens.
Only the x/y offsets are effective with the current code.

> I
> know it worked at one point at least, but that may have been back in
> the UMS days...

Before my time.

-- 
Ville Syrjälä
Intel OTC