SRU request for LP#241229

[Stefan Bader]

Wang, Yong Y wrote:
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/241229
> 
> SRU justification:
> 
> The ACPI BIOSes of some problematic machines, e.g. Toshiba Satellite
> L35, only export C1 when running on AC while the same machines support
> more than C1 when running on battery. This results in
> cpuidle_register_device not being called during system initialization
> when running on battery. However, cpuidle_enable_device will be called
> without cpuidle_register_device being called before when user switches
> from AC to DC and _CST changed notification occurs, thus the oops. 
> 
> Upstream bug report can be found at
> http://bugzilla.kernel.org/show_bug.cgi?id=10394 and Cherry picking
> upstream dcb84f335bee9c9a7781cfc5d74492dccaf066d2 can fix it.
> 
> Fix is available below:
> 
> The following changes since commit
> 70cb93e6771963cca14ad9a3d87687484ee02428:
>   Stefan Bader (1):
>         UBUNTU: ACPICA: Fix for resource descriptor optimization issues
> for _CRS/_SRC
> 
> are available in the git repository at:
> 
>   git://kernel.ubuntu.com/ywang/ubuntu-hardy.git master
> 
> Yong Wang (1):
>       UBUNTU: cpuidle acpi driver: fix oops on AC<->DC
> 
>  drivers/acpi/processor_idle.c |   26 +++++++++++++++++++-------
>  drivers/cpuidle/cpuidle.c     |   40
> +++++++++++++++++++++++++++++++++++-----
>  include/linux/cpuidle.h       |    3 ++-
>  3 files changed, 56 insertions(+), 13 deletions(-)
> 
> -Yong
> 
Hi Yong,

looking at your backported patch I noticed that it also introduces an
override option for cpuidle. Was this strictly necessary or rather
because upstream just has this in place and the patch didn't apply
otherwise?

Note to all: while I think the patch looks fairly simple and should not
cause much impact, it still will change the ABI. Should we proceed with
integration (since there is already another patch that changes the ABI)
or rather try a PPA first?

Stefan