Subject: Re: [PATCH] powerpc: Convert power off logic to pm_power_off

From: Alexander Graf <[email-masked]>
Date: Wed, 22 Oct 2014 10:41:31 +0200

On 22.10.14 06:37, Michael Ellerman wrote:
> The generic Linux framework to power off the machine is a function pointer
> called pm_power_off. The trick about this pointer is that device drivers can
> potentially implement it rather than board files.
> 
> Today on powerpc we set pm_power_off to invoke our generic full machine power
> off logic which then calls ppc_md.power_off to invoke machine specific power
> off.
> 
> However, when we want to add a power off GPIO via the "gpio-poweroff" driver,
> this card house falls apart. That driver only registers itself if pm_power_off
> is NULL to ensure it doesn't override board specific logic. However, since we
> always set pm_power_off to the generic power off logic (which will just not
> power off the machine if no ppc_md.power_off call is implemented), we can't
> implement power off via the generic GPIO power off driver.
> 
> To fix this up, let's get rid of the ppc_md.power_off logic and just always use
> pm_power_off as was intended. Then individual drivers such as the GPIO power off
> driver can implement power off logic via that function pointer.
> 
> With this patch set applied and a few patches on top of QEMU that implement a
> power off GPIO on the virt e500 machine, I can successfully turn off my virtual
> machine after halt.
> 
> Signed-off-by: Alexander Graf <[email-masked]>
> [mpe: Squash into one patch and update changelog based on cover letter]
> Signed-off-by: Michael Ellerman <[email-masked]>
> ---
>  arch/powerpc/include/asm/machdep.h               |  1 -
>  arch/powerpc/kernel/setup-common.c               |  6 +--
>  arch/powerpc/platforms/44x/ppc476.c              |  2 +-
>  arch/powerpc/platforms/52xx/efika.c              |  3 +-
>  arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c   |  8 ++--
>  arch/powerpc/platforms/85xx/corenet_generic.c    |  2 +-
>  arch/powerpc/platforms/85xx/sgy_cts1000.c        |  4 +-
>  arch/powerpc/platforms/cell/celleb_setup.c       |  4 +-
>  arch/powerpc/platforms/cell/qpace_setup.c        |  2 +-
>  arch/powerpc/platforms/cell/setup.c              |  2 +-
>  arch/powerpc/platforms/chrp/setup.c              |  3 +-
>  arch/powerpc/platforms/embedded6xx/gamecube.c    |  3 +-
>  arch/powerpc/platforms/embedded6xx/linkstation.c |  4 +-
>  arch/powerpc/platforms/embedded6xx/wii.c         |  3 +-
>  arch/powerpc/platforms/maple/setup.c             |  4 +-
>  arch/powerpc/platforms/powermac/setup.c          |  3 +-
>  arch/powerpc/platforms/powernv/setup.c           |  4 +-
>  arch/powerpc/platforms/ps3/setup.c               |  2 +-
>  arch/powerpc/platforms/pseries/setup.c           | 59 ++++++++++++------------
>  arch/powerpc/sysdev/fsl_soc.c                    |  2 +-
>  arch/powerpc/xmon/xmon.c                         |  3 +-
>  21 files changed, 66 insertions(+), 58 deletions(-)
> 
> 
> Hi guys, how does this look?
> 
> If it's OK I'll put it in a topic branch for Guenter.

Looks good to me. Thanks for doing the cleanup :).

Alex