[Intel-gfx] [PATCH] drm/i915: Mark fastboot as unsafe

[Jesse Barnes]

On Fri, 7 Nov 2014 18:41:16 +0100
Daniel Vetter <daniel at ffwll.ch> wrote:

> On Tue, Nov 04, 2014 at 03:29:57PM +0100, Daniel Vetter wrote:
> > Fastboot in its current incarnation assumes that the pfit isn't
> > relevatn for the state and that it can be disabled without
> > restarting the crtc. Unfortunately that's not the case on gen2/3 -
> > it upsets the hw and results in a black screen.
> > 
> > Worse, the way the current fastboot hack is structure we can't
> > detect and work around this in the code, since the fastboot smashes
> > the adjusted mode into crtc->mode. Which means the higher levels
> > can't correctly figure out that this is a lie and act accordingly.
> > 
> > Since fastboot is just a tech demo let's mark the module option as
> > experimental and close the coresponding reports as wontfix.
> > 
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84682
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> 
> Jesse expressed concerns in private about this patch, so I've dropped
> it and the other fastboot patch.

I don't think this patch addresses the referenced bug, and it also
implies that we don't care about ever making fastboot the default, so
can ignore any related buts.  The latter surely isn't true in my mind
at least, which is why I've been pushing additional fixes, as recently
as the same day as this patch, so I'm a bit confused about the summary.

As for pfit handling issues, can you be more specific about the case
you want to support that we don't today?  The recent patch for checking
whether pfit requires a full mode set should address your first point,
but I don't know what exactly you mean in your second paragraph...

Thanks,
Jesse