Re: [PATCH v5 5/5] dell-rbtn: Add a comment about the XPS 13 9350

[Mario Limonciello <mario_limonciello@dell.com>]

On 02/17/2016 05:16 AM, Pali Rohár wrote:
> On Monday 15 February 2016 08:32:37 Andy Lutomirski wrote:
>> On the XPS 13 9350, the dell-rbtn mechanism has a new device id, and
>> the DSDT turns it off if a new enough _OSI is supported.  Add a
>> comment about why we don't bother supporting it.
>>
>> Signed-off-by: Andy Lutomirski <luto@kernel.org>
>> ---
>>  drivers/platform/x86/dell-rbtn.c | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
>>
>> diff --git a/drivers/platform/x86/dell-rbtn.c b/drivers/platform/x86/dell-rbtn.c
>> index cd410e392550..b51a2008d782 100644
>> --- a/drivers/platform/x86/dell-rbtn.c
>> +++ b/drivers/platform/x86/dell-rbtn.c
>> @@ -217,6 +217,21 @@ static void rbtn_notify(struct acpi_device *device, u32 event);
>>  static const struct acpi_device_id rbtn_ids[] = {
>>  	{ "DELRBTN", 0 },
>>  	{ "DELLABCE", 0 },
>> +
>> +	/*
>> +	 * 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.
> Do you know reason for such behaviour? It is because event is send
> duplicated (by dell-rbtn and also by intel-hid)?
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.
>> +	 * 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.
>> +	 */
>> +
>>  	{ "", 0 },
>>  };
>>