Re: [PATCH] ACPI / scan: Always call acpi_bus_scan() for bus check notifications

Rafael J. Wysocki
2013-07-10T00:01:22Z

On Tuesday, July 09, 2013 01:32:42 PM Toshi Kani wrote:
> On Mon, 2013-07-08 at 02:10 +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > An ACPI_NOTIFY_BUS_CHECK notification means that we should scan the
> > entire namespace starting from the given handle even if the device
> > represented by that handle is present (other devices below it may
> > just have been added).
> >
> > For this reason, modify acpi_scan_bus_device_check() to always run
> > acpi_bus_scan() if the notification being handled is of type
> > ACPI_NOTIFY_BUS_CHECK.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > Cc: 3.10+ <stable@vger.kernel.org>
>
> Acked-by: Toshi Kani <toshi.kani@hp.com>
>
> But, I think we need the additional patch below.

Yes, I think you're right.

Thanks,
Rafael

> =====
> From: Toshi Kani <toshi.kani@hp.com>
> Subject: [PATCH] ACPI: Do not call attach() if device is attached
>
> attach() of ACPI scan handlers does not expect to be called multiple
> times on a same device. Also, the attached handler may not be changed
> without calling its detach(). Change acpi_scan_attach_handler() not
> to call attach() when the given device is already attached.
>
> Signed-off-by: Toshi Kani <toshi.kani@hp.com>
> ---
> drivers/acpi/scan.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 20757e0..2b9e867 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1885,6 +1885,9 @@ static int acpi_scan_attach_handler(struct
> acpi_device *device)
> struct acpi_hardware_id *hwid;
> int ret = 0;
>
> + if (device->handler)
> + return 1;
> +
> list_for_each_entry(hwid, &device->pnp.ids, list) {
> const struct acpi_device_id *devid;
> struct acpi_scan_handler *handler;
>
>
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--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.