[PATCH][V4] powerpc/fsl-pci: Add pci inbound/outbound PM support

[Kumar Gala]

On Sep 19, 2012, at 2:10 AM, Jia Hongtao-B38951 wrote:

> 
> 
>> -----Original Message-----
>> From: Kumar Gala [mailto:galak at kernel.crashing.org]
>> Sent: Tuesday, September 18, 2012 1:04 PM
>> To: Jia Hongtao-B38951
>> Cc: linuxppc-dev at lists.ozlabs.org; Li Yang-R58472; Wood Scott-B07421
>> Subject: Re: [PATCH][V4] powerpc/fsl-pci: Add pci inbound/outbound PM
>> support
>> 
>> 
>> On Sep 17, 2012, at 9:10 PM, 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>
>>> ---
>>> Changes for V4:
>>> We just rebase the patch upon following patch:
>>> powerpc/fsl-pci: Unify pci/pcie initialization code
>>> 
>>> arch/powerpc/include/asm/pci-bridge.h |    2 +-
>>> arch/powerpc/sysdev/fsl_pci.c         |  121
>> +++++++++++++++++++++++++++++++++
>>> 2 files changed, 122 insertions(+), 1 deletions(-)
>> 
>> Did you ever compare this to just re-parsing device tree method?
>> 
>> - k
> 
> I tested the re-parsing way by using setup_pci_atmu() when resume.
> And I found out that re-parsing will *change* outbound IO translation
> address regitster.
> 
> It seems that in the first bootup, after setup_atmu()
> pcibios_setup_phb_resources() may update hose->io_resource, but atmu
> is not updated according to the new hose->io_resource value.
> In resume from sleep setup_atmu() will reset atmu according to the
> new hose->io_resource value. So the setup_atmu() will cause different
> result on outbound IO register between first bootup and resume from
> sleep.
> 
> So... There's a possibility that in the first bootup atmu is not setup
> properly.

Are you seeing this happen in your testing?  If so its a bug we need to look at fixing.

> 
> Anyway, if setup_pci_atmu() at resume is functionally right then re-parsing
> is a good way for PM. I also test the latency of re-parsing and save/restore,
> both way are acceptable.
> 
> 
> - Hongtao.