Re: [linux-pm] [RFC,PATCHv3 0/3] sdhci runtime_pm implementation

[Pierre Tardy]

On Tue, Mar 1, 2011 at 8:57 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, 1 Mar 2011, Pierre Tardy wrote:
>
>> On Tue, Mar 1, 2011 at 8:33 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>> > On Tue, 1 Mar 2011, Pierre Tardy wrote:
>> >
>> >> Please find sdhci runtime_pm implementation.
>> >>
>> >> It uses clock gating fw as a tip to know when our chip is idle.
>> >> It implements wake up from card insertion/removal.
>> >>
>> >> This is RFC, please dont merge yet. I really would like to have deep review
>> >> from PCI linux-pm guys.
>> >>
>> >> Opens are:
>> >>
>> >> 1/ Not sure if the pci configs in the driver in rpm_suspend/resume flow
>> >>  are not duplicate from what the core is doing.
>> >
>> > There may be one or two small errors.
>> >
>> >> 2/ Wakeup from D3hot: I cannot find any driver that is implementing it in current upstream,
>> >
>> > Other drivers do it, but they use PCI PME# instead of interrupts.
>> Could you please elaborate?
>> My understanding is that PCI PME will generate MSI, which translate in
>> interrupt.
>
> It depends on the platform.  On systems with ACPI, PCI PME generates an
> ACPI I/O event, which is handled by the ACPI and PM cores.  It does not
> invoke the device driver's interrupt handler.
So, let's say, in the ACPI case, if the interrupt handler dont get
called, how would the driver know that he got a sdcard insert event,
and trigger a mmc_rescan() ?

Regards,
Pierre
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