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

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Sun, Nov 25, 2012 at 03:58:14PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> 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@intel.com>

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>