[PATCH 5/6] powerpc/fsl-pci: Add pci inbound/outbound PM support

[Jia Hongtao-B38951]

> -----Original Message-----
> From: Kumar Gala [mailto:galak at kernel.crashing.org]
> Sent: Friday, July 27, 2012 9:24 PM
> To: Jia Hongtao-B38951
> Cc: linuxppc-dev at lists.ozlabs.org; Wood Scott-B07421; Li Yang-R58472
> Subject: Re: [PATCH 5/6] powerpc/fsl-pci: Add pci inbound/outbound PM
> support
> 
> 
> On Jul 24, 2012, at 5:20 AM, Jia Hongtao wrote:
> 
> > Power supply for PCI inbound/outbound window registers is off when
> system
> > go to deep-sleep state. We save the values of registers before suspend
> > and restore to registers after resume.
> >
> > Signed-off-by: Jiang Yutang <b14898 at freescale.com>
> > Signed-off-by: Jia Hongtao <B38951 at freescale.com>
> > Signed-off-by: Li Yang <leoli at freescale.com>
> > ---
> > arch/powerpc/include/asm/pci-bridge.h |    2 +-
> > arch/powerpc/sysdev/fsl_pci.c         |  121
> +++++++++++++++++++++++++++++++++
> > 2 files changed, 122 insertions(+), 1 deletions(-)
> 
> Remind me why we need to save/restore PCI ATMUs, why not just re-parse
> the device tree to restore?
> 
> - k

Save/restore is the more efficient way. Latency of sleep/wakeup is one of
most important features in power management.

-Hongtao.