On Wed, Jun 13, 2012 at 03:26:00PM -0500, Seth Forshee wrote: > On Wed, Jun 13, 2012 at 09:46:15PM +0200, Daniel Vetter wrote: > > On Wed, Jun 13, 2012 at 01:46:58PM -0500, Seth Forshee wrote: > > > The Lenovo Thinkpad T410 has the LVDS_PIPEB_SELECT bit set in the LVDS > > > register when booted with the lid closed, even though the LVDS hasn't > > > really been initialized. Ignore this bit so that the VBT value will be > > > used instead. > > > > > > Signed-off-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx> > > Queued for -next, thanks for the patch. Chris had some reservations about > > the sanity of this patch, but given that it works around bios-insanity I'm > > gonna just take this chance to stab myself with lvds-machines blowing up > > left and right ;-) > > Let's hope that doesn't happen ;) > > I do find myself wondering though whether it might be better to prefer > the value from the VBT whenever there's one available, and only rely on > the actual register value as a fallback, since the bios can't be trusted > to initialize the register. I'm pretty ignorant about all this graphics > stuff though; I assume there's a reason it isn't done this way? The usual reasoning is that if it's in the register, it's the value that makes something show up on the screen and hence has a higher change of being right. Yep, BIOS routinely store total garbage in vbt (or the newer OpRegion) and somehow fix that up when copying things to the hw :( Obviously there's also the other case where the hw values aren't set up, in which case we try to try to fall back to vbt values. -Daniel -- Daniel Vetter Mail: daniel@xxxxxxxx Mobile: +41 (0)79 365 57 48 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
