Re: [PATCH 6/6] drm/i915: Reject page flips with changed format/offset/pitch

[Daniel Vetter <daniel@ffwll.ch>]

On Thu, Jul 19, 2012 at 02:27:47PM +0200, Laurent Pinchart wrote:
> Hi Daniel,
> 
> On Thursday 05 July 2012 13:31:17 Daniel Vetter wrote:
> > On Thu, May 24, 2012 at 09:08:59PM +0300, ville.syrjala@linux.intel.com 
> wrote:
> > > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > 
> > > MI display flips can't handle some changes in the framebuffer
> > > format or layout. Return an error in such cases.
> > > 
> > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Queued for -next, thanks for the patch. I've punted on the others, hoping
> > for a few i-g-t tests (and maybe someone else that could review them).
> > Safe for the uninitialized stack var patch and this one, because we need
> > this check to fix up gen4+ tileoffset limitations.
> > 
> > Yours, Daniel
> > 
> > > ---
> > > 
> > >  drivers/gpu/drm/i915/intel_display.c |   13 +++++++++++++
> > >  1 files changed, 13 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/intel_display.c
> > > b/drivers/gpu/drm/i915/intel_display.c index f4338cb..72ac2f9 100644
> > > --- a/drivers/gpu/drm/i915/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/intel_display.c
> > > @@ -6217,6 +6217,19 @@ static int intel_crtc_page_flip(struct drm_crtc
> > > *crtc,> 
> > >  	unsigned long flags;
> > >  	int ret;
> > > 
> > > +	/* Can't change pixel format via MI display flips. */
> > > +	if (fb->pixel_format != crtc->fb->pixel_format)
> > > +		return -EINVAL;
> 
> Is this still needed if we apply my "drm: Don't allow page flip to change 
> pixel format" patch ?

Actually, drm/i915 is on track to grow itself a complete new modeset
implementation which does not use the crtc helpers (at least as little as
possible). See

http://cgit.freedesktop.org/~danvet/drm/log/?h=modeset-rework

Cheers, Daniel

> 
> > > +	/*
> > > +	 * TILEOFF/LINOFF registers can't be changed via MI display flips.
> > > +	 * Note that pitch changes could also affect these register.
> > > +	 */
> > > +	if (INTEL_INFO(dev)->gen > 3 &&
> > > +	    (fb->offsets[0] != crtc->fb->offsets[0] ||
> > > +	     fb->pitches[0] != crtc->fb->pitches[0]))
> > > +		return -EINVAL;
> > > +
> > > 
> > >  	work = kzalloc(sizeof *work, GFP_KERNEL);
> > >  	if (work == NULL)
> > >  	
> > >  		return -ENOMEM;
> 
> -- 
> Regards,
> 
> Laurent Pinchart
> 

-- 
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48