> -----Original Message----- > From: Linuxppc-dev [mailto:linuxppc-dev- > bounces+b38951=freescale....@lists.ozlabs.org] On Behalf Of Kumar Gala > Sent: Wednesday, August 08, 2012 8:47 PM > To: Jia Hongtao-B38951 > Cc: 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 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 does the PCI code know you're entering deep sleep and not > hibernation? > >> > >> -Scott > > > > When system come back from hibernation PCI will be initialized again. > > So no need to save PCI_CMD and PEXCSRBAR. > > > > -Hongtao. > > > > What do you mean PCI will be initialized again? What code path are you > talking about that would set PCI_CMD & PEXCSRBAR? > > - k
In hibernation mode: When system come back from hibernation kernel will start up again. Before loading hibernation image PCI initialization has already done. Some other hardware also re-init again. -Hongtao. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
