> On Thu, 15 May 2008, Justin Madru wrote:
> > I've reported this problem previously:
> >
http://lkml.org/lkml/2008/3/12/290
> >
http://bugzilla.kernel.org/show_bug.cgi?id=10235
> >
https://bugs.freedesktop.org/show_bug.cgi?id=15602
> >
> > This bug is still in mainline as of 2.6.26-rc1. (affected versions 2.6.25-rc0
> > - 2.6.26-rc1)
> >
> > Ever since 2.6.25-rc3 (the first rc I tested), my screen would blank out when
> > mode switching from the Ubuntu uplash to the gdm login. Normally after the
> > boot splash, the screen goes black and "refreshes" to select the correct
> > resolution. But when using a kernel newer than 2.6.24 the screen doesn't come
> > back on - it stays blank. This doesn't happen every time, but a good majority
> > of the time. The workaround is to disable the splash, and that fixes the
> > problem almost completely.
> >
> > I did a git bisect. Rebooting 3 times if the problem didn't occur just to make
> > sure.
> > The git bisect reports that it's timing related - which is what Jesse Barnes
> > said it could be.
>
> Well, it's a timing problem related to splash which is exposed by the
> scheduler timing changes. This is neither a hrtimer nor a scheduler
> bug. Something in the splash / video driver switchover relies on some
> obscure timing which is nowhere guaranteed.
