[Intel-gfx] [PATCH 1/6] drm/i915: unconditionally copy mode into crtc at boot time

[Jesse Barnes]

On Thu, 12 Dec 2013 23:39:39 +0100
Daniel Vetter <daniel at ffwll.ch> wrote:

> On Thu, Dec 12, 2013 at 01:29:39PM -0800, Jesse Barnes wrote:
> > On Thu, 12 Dec 2013 22:21:29 +0100
> > Daniel Vetter <daniel at ffwll.ch> wrote:
> > 
> > > On Thu, Dec 12, 2013 at 12:41:52PM -0800, Jesse Barnes wrote:
> > > > The BIOS code will need this to properly inherit the mode.
> > > > 
> > > > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
> > > > ---
> > > >  drivers/gpu/drm/i915/intel_display.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > > > index af3717a..1ae3d44 100644
> > > > --- a/drivers/gpu/drm/i915/intel_display.c
> > > > +++ b/drivers/gpu/drm/i915/intel_display.c
> > > > @@ -11175,7 +11175,7 @@ void intel_modeset_setup_hw_state(struct drm_device *dev,
> > > >  	 */
> > > >  	list_for_each_entry(crtc, &dev->mode_config.crtc_list,
> > > >  			    base.head) {
> > > > -		if (crtc->active && i915_fastboot) {
> > > > +		if (crtc->active) {
> > > 
> > > That's just enabling half of the fastboot hack, so nacked.
> > 
> > This part isn't the hack, but is required for fastboot.  Without this,
> > we'll end up with a bogus mode when we try to inherit from the BIOS.
> > So if you want to nack this I'll have to put the other BIOS bits under
> > fastboot as well.
> 
> crtc->config.pipe_src_w/h not good enough? I've thought that's what you've
> used in the last iteration, hence my suprise why we suddenly need to
> resurrect this hack here. All the information this hack exposes to
> crtc->mode is available in the pipe config, so I really don't think you
> neeed it.
> 
> Count me confused for now, please explain.

Yes, we read out all the data into the pipe config.  But if we don't
put that data into the CRTC proper, any subsequent code that uses the
CRTC mode will fail and think there's nothing there (resulting in fail
at fbcon DPMS time for example).

-- 
Jesse Barnes, Intel Open Source Technology Center