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

[Kumar Gala]

On Jul 30, 2012, at 1:09 AM, Jia Hongtao-B38951 wrote:

>> -----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.

I don't think the time it takes to run through setup_pci_atmu() is that long compared to fsl_pci_resume().

Also, don't you need to setup PCICCSRBAR and do setup_pci_cmd() on resume?

- k