Re: [PATCH 2/2] platform / ACPI: Attach/detach ACPI PM during probe/remove/shutdown

From: Rafael J. Wysocki
Date: Sun Nov 25 2012 - 14:53:09 EST


On Sunday, November 25, 2012 10:42:25 AM Greg Kroah-Hartman wrote:
> On Sun, Nov 25, 2012 at 03:58:14PM +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> > Drivers usually expect that the devices they are supposed to handle
> > will be operational when their .probe() routines are called, but that
> > need not be the case on some ACPI-based systems with ACPI-based
> > device enumeration where the BIOSes don't put devices into D0 by
> > default. To work around this problem it is sufficient to change
> > bus type .probe() routines to ensure that devices will be powered
> > on before the drivers' .probe() routines run (and their .remove()
> > and .shutdown() routines accordingly).
> >
> > Modify platform_drv_probe() to run acpi_dev_pm_attach() for devices
> > whose ACPI handles are present, so that ACPI power management is used
> > to change their power states and change their power states to D0
> > before driver probing. Analogously, modify platform_drv_remove() and
> > platform_drv_shutdown() to call acpi_dev_pm_detach() for those
> > devices, so that they are not subject to ACPI PM any more.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Thanks!


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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