On Friday, February 17, 2012, Lin Ming wrote: > 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. It seems that you can use pm_runtime_no_callbacks() to work around this as suggested by Alan. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html