On Sat, May 27, 2017 at 8:16 AM, Darren Hart <dvhart@xxxxxxxxxxxxx> wrote:
> From: Andy Lutomirski <luto@xxxxxxxxxx>
>
> According to Mario at Dell, the DELLABC6 device should not be used on a
> Linux system. It also conflicts with Intel-HID and its interactions with
> Network Manager. Document that we are aware of the device, but that we
> are intentionally ignoring it.
>
Pali made a good point.
Otherwise, FWIW:
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
> [dvhart: New commit message and minor comment wording fixes]
> Cc: Mario Limonciello <mario_limonciello@xxxxxxxx>
> Cc: "Pali Rohár" <pali.rohar@xxxxxxxxx>
> Signed-off-by: Darren Hart (VMware) <dvhart@xxxxxxxxxxxxx>
> ---
> drivers/platform/x86/dell-rbtn.c | 26 +++++++++++++++++++-------
> 1 file changed, 19 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/platform/x86/dell-rbtn.c b/drivers/platform/x86/dell-rbtn.c
> index dcd9f40..2eeef03 100644
> --- a/drivers/platform/x86/dell-rbtn.c
> +++ b/drivers/platform/x86/dell-rbtn.c
> @@ -223,14 +223,26 @@ static const struct acpi_device_id rbtn_ids[] = {
> * This driver can also handle the "DELLABC6" device that
> * appears on the XPS 13 9350, but that device is disabled
> * by the DSDT unless booted with acpi_osi="!Windows 2012"
> - * acpi_osi="!Windows 2013". Even if we boot that and bind
> - * the driver, we seem to have inconsistent behavior in
> - * which NetworkManager can get out of sync with the rfkill
> - * state.
> + * acpi_osi="!Windows 2013".
> *
> - * On the XPS 13 9350 and similar laptops, we're not supposed to
> - * use DELLABC6 at all. Instead, we handle the rfkill button
> - * via the intel-hid driver.
> + * According to Mario at Dell:
> + *
> + * DELLABC6 is a custom interface that was created solely to
> + * have airplane mode support for Windows 7. For Windows 10
> + * the proper interface is to use that which is handled by
> + * intel-hid. A OEM airplane mode driver is not used.
> + *
> + * Since the kernel doesn't identify as Windows 7 it would be
> + * incorrect to do attempt to use that interface.
> + *
> + * Even if we override _OSI and bind to DELLABC6, we end up
> + * with inconsistent behavior in which NetworkManager can get
> + * out of sync with the rfkill state. This happens because
> + * NetworkManager receives events from intel-hid and fights with
> + * dell-rbtn for control.
> + *
> + * The upshot is that it's better to just ignore DELLABC6
> + * devices.
> */
>
> { "", 0 },
> --
> 2.9.4
>
--
With Best Regards,
Andy Shevchenko
