platform/x86: intel-hid: Fix spurious wakeups caused by tablet-mode events during...

Some devices send (duplicate) tablet-mode events when moved around even
though the mode has not changed; and they do this even when suspended.

Change the tablet-mode event handling when priv->wakeup_mode is set to
update the switch state in case it changed and then return immediately
(without calling pm_wakeup_hard_event()) to avoid spurious wakeups.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=212537
Fixes: 537b0dd4729e ("platform/x86: intel-hid: Add support for SW_TABLET_MODE")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Elia Devito <eliadevito@gmail.com>
Link: https://lore.kernel.org/r/20210404143831.25173-1-hdegoede@redhat.com

diff --git a/drivers/platform/x86/intel-hid.c b/drivers/platform/x86/intel-hid.c
index 57cc928..078648a 100644 (file)
--- a/drivers/platform/x86/intel-hid.c
+++ b/drivers/platform/x86/intel-hid.c
@@ -483,11 +483,16 @@ static void notify_handler(acpi_handle handle, u32 event, void *context)
                        goto wakeup;
 
                /*
-                * Switch events will wake the device and report the new switch
-                * position to the input subsystem.
+                * Some devices send (duplicate) tablet-mode events when moved
+                * around even though the mode has not changed; and they do this
+                * even when suspended.
+                * Update the switch state in case it changed and then return
+                * without waking up to avoid spurious wakeups.
                 */
-               if (priv->switches && (event == 0xcc || event == 0xcd))
-                       goto wakeup;
+               if (event == 0xcc || event == 0xcd) {
+                       report_tablet_mode_event(priv->switches, event);
+                       return;
+               }
 
                /* Wake up on 5-button array events only. */
                if (event == 0xc0 || !priv->array)
@@ -501,9 +506,6 @@ static void notify_handler(acpi_handle handle, u32 event, void *context)
 wakeup:
                pm_wakeup_hard_event(&device->dev);
 
-               if (report_tablet_mode_event(priv->switches, event))
-                       return;
-
                return;
        }