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| author | Andy Lutomirski <luto@kernel.org> | 2016-02-17 12:43:06 -0800 |
|---|---|---|
| committer | Darren Hart (VMware) <dvhart@infradead.org> | 2017-06-03 12:23:43 -0700 |
| commit | 5d4be5f2b1f1919ffbf1ca5c9c014692848bafd1 (patch) | |
| tree | e68248bb555630f99ec3b2b0e9a5f777dc3c754a /drivers/platform/x86/dell-rbtn.c | |
| parent | e4f2e3f0ea13cf3424c0f23d01424c68a428333b (diff) | |
| download | lwn-5d4be5f2b1f1919ffbf1ca5c9c014692848bafd1.tar.gz lwn-5d4be5f2b1f1919ffbf1ca5c9c014692848bafd1.zip | |
platform/x86: dell-rbtn: Improve explanation about DELLABC6
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.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
[dvhart: New commit message and minor comment wording fixes]
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: "Pali Rohár" <pali.rohar@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Diffstat (limited to 'drivers/platform/x86/dell-rbtn.c')
| -rw-r--r-- | drivers/platform/x86/dell-rbtn.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/platform/x86/dell-rbtn.c b/drivers/platform/x86/dell-rbtn.c index dcd9f40a4b18..f5c53ea87158 100644 --- a/drivers/platform/x86/dell-rbtn.c +++ b/drivers/platform/x86/dell-rbtn.c @@ -221,16 +221,27 @@ 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. + * 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". * - * 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 userspace can get out of sync + * with the rfkill state as it conflicts with events from + * intel-hid. + * + * The upshot is that it is better to just ignore DELLABC6 + * devices. */ { "", 0 }, |