Re: Baytrail/T (ASUS T100 etc) regression from 3.13 onwards

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Feb 11, 2014 at 10:11:37AM -0800, Jesse Barnes wrote:
> On Tue, 11 Feb 2014 08:35:41 -0800
> Greg KH <gregkh@linuxfoundation.org> wrote:
> 
> > On Tue, Feb 11, 2014 at 02:22:03PM +0000, One Thousand Gnomes wrote:
> > > On Tue, 14 Jan 2014 12:01:03 +0000
> > > One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> wrote:
> > > 
> > > > On Sun, 12 Jan 2014 20:33:03 +0700
> > > > Linus Torvalds <torvalds@linux-foundation.org> wrote:
> > > > 
> > > > > Another week, another RC. And things look fine.
> > > > 
> > > > It seems to hate Baytrail/T
> > > > 
> > > > My ASUS T100TA has gone from 3.11 'needs video=VGA-1:blah' to get the mode
> > > > right but otherwise running nicely and playing 3D games to 3.13-rc8
> > > 
> > > This has now been pinned down to (confirmed by multiple people)
> > > 
> > > commit 6c4a8962a4a078cacfc8eb5d4bd79f6343b8cd7a
> > > Author: Jesse Barnes <jbarnes@virtuousgeek.org>
> > > Date:   Tue Sep 10 14:54:42 2013 -0700
> > > 
> > >     drm/i915/vlv: re-enable hotplug detect based probing on VLV/BYT
> > > 
> > > 
> > > which given this is affecting some of the top 10 Amazon selling new
> > > laptops and has not been fixed for 3.14-rc should IMHO be reverted until
> > > such time as any needed debugging for the MIPI panels is done for this
> > > driver and the hotplug probing doesn't break the workarounds.
> > > 
> > > Likewise it wants pulling from any -stable backports.
> > 
> > I only see it in the 3.13 tree, so when this gets reverted in Linus's
> > tree, can someone mark it for stable so I know to pick it up for
> > 3.13-stable as well?
> 
> Ugg, so reverting a real fix to make the T100TA work by accident...
> this is ugly.
> 
> According to the reg dumps, this is actually a MIPI panel we're failing
> to bring up properly.  We're working on that issue, but in the
> meantime, maybe something like the below would work for you?

A module paramater to fix a bug?  Ugh, that's almost worse than just
reverting the original patch, right?

Please don't do this, the distros will hate you even more than they
currently do :)

greg k-h