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

[Jia Hongtao-B38951]

> -----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.

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.