2013-03-18 10:05:29

by Daniel Vetter

Subject: Revert a bunch of patches in stable kernels

Hi Greg&all,

So a recent stable backport to fix rc6 on ilk (which is disabled by
default and with dubious power savings at best, unlike rc6 on snb and
later) totally blew up all over the place:
https://bugzilla.kernel.org/show_bug.cgi?id=55291
https://lkml.org/lkml/2013/3/14/540

There might be more, I'm still recovering from mail floods due to
traveling last week. I think the right course of action is to revert
the offending patch (plus anything depending upon it) and give up on
rc6 on ilk in 3.8 - too messy. All bug reports confirmed that 3.9-rc
kernels work as expected. Upstream commits to revert:

15239099d7a7a9ecdc1ccb5b187ae4cda5488ff9 drm/i915: enable irqs earlier
when resuming
52d7ecedac3f96fb562cb482c139015372728638 drm/i915: reorder setup
sequence to have irqs for output setup

Cheers, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

2013-03-18 15:40:23

by Daniel Vetter

Subject: Re: Revert a bunch of patches in stable kernels

On Mon, Mar 18, 2013 at 11:05 AM, Daniel Vetter <[email protected]> wrote:
> Hi Greg&all,
>
> So a recent stable backport to fix rc6 on ilk (which is disabled by
> default and with dubious power savings at best, unlike rc6 on snb and
> later) totally blew up all over the place:
> https://bugzilla.kernel.org/show_bug.cgi?id=55291
> https://lkml.org/lkml/2013/3/14/540

This likely also is the culprit behind the ghost vga issues reported
on gm45, e.g:

https://bugzilla.redhat.com/show_bug.cgi?id=922304

Again, fixed in 3.9-rc kernels by

commit 20afbda209d708be66944907966486d0c1331cb8
Author: Daniel Vetter <[email protected]>
Date: Tue Dec 11 14:05:07 2012 +0100

drm/i915: Fixup hpd irq register setup ordering

Cheers, Daniel

> There might be more, I'm still recovering from mail floods due to
> traveling last week. I think the right course of action is to revert
> the offending patch (plus anything depending upon it) and give up on
> rc6 on ilk in 3.8 - too messy. All bug reports confirmed that 3.9-rc
> kernels work as expected. Upstream commits to revert:
>
> 15239099d7a7a9ecdc1ccb5b187ae4cda5488ff9 drm/i915: enable irqs earlier
> when resuming
> 52d7ecedac3f96fb562cb482c139015372728638 drm/i915: reorder setup
> sequence to have irqs for output setup
>
> Cheers, Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch



--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

2013-03-18 20:17:15

by Greg Kroah-Hartman

Subject: Re: Revert a bunch of patches in stable kernels

On Mon, Mar 18, 2013 at 11:05:26AM +0100, Daniel Vetter wrote:
> Hi Greg&all,
>
> So a recent stable backport to fix rc6 on ilk (which is disabled by
> default and with dubious power savings at best, unlike rc6 on snb and
> later) totally blew up all over the place:
> https://bugzilla.kernel.org/show_bug.cgi?id=55291
> https://lkml.org/lkml/2013/3/14/540
>
> There might be more, I'm still recovering from mail floods due to
> traveling last week. I think the right course of action is to revert
> the offending patch (plus anything depending upon it) and give up on
> rc6 on ilk in 3.8 - too messy. All bug reports confirmed that 3.9-rc
> kernels work as expected. Upstream commits to revert:
>
> 15239099d7a7a9ecdc1ccb5b187ae4cda5488ff9 drm/i915: enable irqs earlier
> when resuming
> 52d7ecedac3f96fb562cb482c139015372728638 drm/i915: reorder setup
> sequence to have irqs for output setup

Thanks for tracking this down, I've reverted both of these patches now,
which should hopefully fix the issues reported.

greg k-h