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.
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
