On Thu, 2012-02-16 at 10:13 -0500, Alan Stern wrote:
> On Thu, 16 Feb 2012, Zhang Rui wrote:
>
> > > I'm not exactly sure what you're trying to achieve and what you mean by
> > > "resume a device directly"? Do you want to run the device's resume
> > > callback at the time when another device is being resumed?
> > >
> > I mean, wakeup event is sent to ATA port, but our goal is to resume
> > ZPODD after receiving this wakeup event.
> > Ideally, it is ACPI that resumes ATA port. And then, the ATA port
> > runtime resumes ZPODD. But this does not look good to runtime resume a
> > child device in the parent's .runtime_resume callback.
> > So I introduced these two APIs so that an runtime_resume request can be
> > sent to ZPODD directly and the runtime PM core can resume all the
> > parents of ZPODD automatically.
>
> It's not clear what you're trying to achieve. Do you basically want
> the ZPODD always to be suspended and resumed along with the ATA port,
> or should it be possible to suspend the ZPODD while the port remains
> running?
We want to ZPODD always to be suspended and resumed along with the ATA
port.
Below is part of the GPE handler for ZPODD device attention event.
Scope (\_GPE)
{
Method (_L13, 0, NotSerialized)
{
ADBG ("ZPODD DA Event")
....
Notify (\_SB.PCI0.SAT0.PRT2, 0x02)
....
}
}
It maybe a bit confused, but actually, \_SB.PCI0.SAT0.PRT2 is bind to
the attached device, not the ata port itself.
See below commit in linux-next tree.
75d22c(libata: Bind the Linux device tree to the ACPI device tree)
And below notify handler(PATCH 6) will resume the attached device(CDROM
in ZPODD case).
+static void ata_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
+{
+ struct ata_device *ata_dev = context;
+
+ if (event == ACPI_NOTIFY_DEVICE_WAKE && ata_dev)
+ scsi_autopm_get_device(ata_dev->sdev);
+}
+
But the code to power on/power off the device is in ata_acpi_set_state,
which is called when ata port is resumed/suspended.
ata_eh_handle_port_resume/suspend
ata_acpi_set_state
ata_for_each_dev {
acpi_bus_set_power(<the acpi handle of the device>, acpi_state)
}
Could you take a look at PATCH 6?
It's more clear over there.
Thanks,
Lin Ming
>
> Alan Stern
>
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