platform/x86: intel-vbtn: Stop reporting SW_DOCK events

Stop reporting SW_DOCK events because this breaks suspend-on-lid-close.

SW_DOCK should only be reported for docking stations, but all the DSDTs in
my DSDT collection which use the intel-vbtn code, always seem to use this
for 2-in-1s / convertibles and set SW_DOCK=1 when in laptop-mode (in tandem
with setting SW_TABLET_MODE=0).

This causes userspace to think the laptop is docked to a port-replicator
and to disable suspend-on-lid-close, which is undesirable.

Map the dock events to KEY_IGNORE to avoid this broken SW_DOCK reporting.

Note this may theoretically cause us to stop reporting SW_DOCK on some
device where the 0xCA and 0xCB intel-vbtn events are actually used for
reporting docking to a classic docking-station / port-replicator but
I'm not aware of any such devices.

Also the most important thing is that we only report SW_DOCK when it
reliably reports being docked to a classic docking-station without any
false positives, which clearly is not the case here. If there is a
chance of reporting false positives then it is better to not report
SW_DOCK at all.

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210321163513.72328-1-hdegoede@redhat.com

diff --git a/drivers/platform/x86/intel-vbtn.c b/drivers/platform/x86/intel-vbtn.c
index 8a8017f..3fdf4cb 100644 (file)
--- a/drivers/platform/x86/intel-vbtn.c
+++ b/drivers/platform/x86/intel-vbtn.c
@@ -48,8 +48,16 @@ static const struct key_entry intel_vbtn_keymap[] = {
 };
 
 static const struct key_entry intel_vbtn_switchmap[] = {
-       { KE_SW,     0xCA, { .sw = { SW_DOCK, 1 } } },          /* Docked */
-       { KE_SW,     0xCB, { .sw = { SW_DOCK, 0 } } },          /* Undocked */
+       /*
+        * SW_DOCK should only be reported for docking stations, but DSDTs using the
+        * intel-vbtn code, always seem to use this for 2-in-1s / convertibles and set
+        * SW_DOCK=1 when in laptop-mode (in tandem with setting SW_TABLET_MODE=0).
+        * This causes userspace to think the laptop is docked to a port-replicator
+        * and to disable suspend-on-lid-close, which is undesirable.
+        * Map the dock events to KEY_IGNORE to avoid this broken SW_DOCK reporting.
+        */
+       { KE_IGNORE, 0xCA, { .sw = { SW_DOCK, 1 } } },          /* Docked */
+       { KE_IGNORE, 0xCB, { .sw = { SW_DOCK, 0 } } },          /* Undocked */
        { KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },   /* Tablet */
        { KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },   /* Laptop */
        { KE_END }