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

- From: Jia Hongtao-B38951 \<hidden\>
- Date: 2012-08-08 03:07:27 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2012/08/9470719
- Thread: https://ratatoskr.run/linuxppc-dev/2012/07/9470407/t.md

```text


> -----Original Message-----
> From: Kumar Gala [mailto:<redacted>]
> Sent: Wednesday, August 08, 2012 1:34 AM
> To: Wood Scott-B07421
> Cc: Jia Hongtao-B38951; <redacted>; Wood Scott-B07421;
> Li Yang-R58472
> Subject: Re: [PATCH 5/6] powerpc/fsl-pci: Add pci inbound/outbound PM
> support
>=20
>=20
> On Aug 7, 2012, at 10:34 AM, Scott Wood wrote:
>=20
> > On 08/07/2012 05:11 AM, Jia Hongtao-B38951 wrote:
> >>
> >>
> >>> -----Original Message-----
> >>> From: Kumar Gala [mailto:<redacted>]
> >>> Sent: Tuesday, July 31, 2012 9:37 PM
> >>> To: Jia Hongtao-B38951
> >>> Cc: <redacted>; Wood Scott-B07421; Li Yang-R58472
> >>> Subject: Re: [PATCH 5/6] powerpc/fsl-pci: Add pci inbound/outbound
> >>> PM support
> >>>
> >>>
> >>> On Jul 30, 2012, at 1:09 AM, Jia Hongtao-B38951 wrote:
> >>>
> >>>>> -----Original Message-----
> >>>>> From: Kumar Gala [mailto:<redacted>]
> >>>>> Sent: Friday, July 27, 2012 9:24 PM
> >>>>> To: Jia Hongtao-B38951
> >>>>> Cc: <redacted>; 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 <redacted>
> >>>>>> Signed-off-by: Jia Hongtao <redacted>
> >>>>>> Signed-off-by: Li Yang <redacted>
> >>>>>> ---
> >>>>>> 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
> >>
> >> Hi Kumar,
> >> I did some tests on P1022DS and found out that PCI_CMD and PCICSRBAR
> >> is not lost when system in deep sleep. We don't need to save it.
> >
> > How does the PCI code know you're entering deep sleep and not
> hibernation?
> >
> > -Scott
> >
>=20
> Also, are you sure PCICSRBAR does not need restoring?  I'd be surprised
> if PCICSRBAR was ok, but the ATMUs where not.
>=20
> - k
>=20

PEXCSRBAR is in configuration space and ATMUs are memory map registers.
I guess there are different power supplies.

-Hongtao.
```