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. Can you find anywhere that documents what state will be retained during deep sleep, or ask an appropriate hardware designer? -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
