On Wed, May 02, 2012 at 09:26:36PM +0100, Chris Wilson wrote: > On Wed, 2 May 2012 13:14:59 -0700, Ben Widawsky <ben at bwidawsk.net> wrote: > > On Wed, 2 May 2012 20:43:56 +0100 > > Chris Wilson <chris at chris-wilson.co.uk> wrote: > > When initialising the PLL registers we may have to clear existing state > from the BIOS - that is the PLL may already be enabled. So we need to > disable it, wait for the clocks to settle and then rewrite it. > > The issue came to light when Ben tested > > commit 88ca4bb7974277793e602d88739d4e8f56b89e64 > Author: Jesse Barnes <jbarnes at virtuousgeek.org> > Date: Fri Apr 20 17:11:53 2012 +0100 > > drm/i915: manage PCH PLLs separately from pipes > > and found that booting into a VGA monitor was no longer working. Closer > inspection suggests that it was a pre-existing bug now being hit by the > rearranged code. Perhaps Ben was not even the first person to stumble > upon this bug, https://bugs.freedesktop.org/show_bug.cgi?id=37029. > > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk> > > > Cc: Ben Widawsky <ben at bwidawsk.net> > > > Cc: Jesse Barnes <jbarnes at virtuousgeek.org> > > Reported-and-tested-by: Ben Widawsky <ben at bwidawsk.net> Queued for -next, thanks for the patch. -Daniel -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48
