> -----Original Message----- > From: Wood Scott-B07421 > Sent: Thursday, August 09, 2012 5:04 AM > To: Kumar Gala > Cc: Jia Hongtao-B38951; Wood Scott-B07421; linuxppc-dev@lists.ozlabs.org; > Li Yang-R58472 > Subject: Re: [PATCH 5/6] powerpc/fsl-pci: Add pci inbound/outbound PM > support > > On 08/08/2012 07:46 AM, Kumar Gala wrote: > >>>>>>> > >>>>>>> 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 <b14...@freescale.com> > >>>>>>>> Signed-off-by: Jia Hongtao <b38...@freescale.com> > >>>>>>>> Signed-off-by: Li Yang <le...@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 > >>>> > >>>> 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 do you know you're not just getting lucky? Maybe it only survives > deep sleep up to a certain duration, or under other specific > circumstances.
I tested for more than 10 mins in deep sleep and the result is the same. > > Can you find anywhere that documents what state will be retained during > deep sleep, or ask an appropriate hardware designer? > > -Scott I agree with you that we should find out what state will be retained during deep sleep. But P1022 RM doc has limited information for this. If I can get more information from hardware designer that will be good. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
