1 files changed, 61 insertions, 0 deletions

diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c
index f362883c94e3..1d247bcf2ae2 100644
--- a/drivers/input/joydev.c
+++ b/drivers/input/joydev.c
@@ -747,6 +747,63 @@ static void joydev_cleanup(struct joydev *joydev)
 		input_close_device(handle);
 }
 
+static bool joydev_dev_is_absolute_mouse(struct input_dev *dev)
+{
+	DECLARE_BITMAP(jd_scratch, KEY_CNT);
+
+	BUILD_BUG_ON(ABS_CNT > KEY_CNT || EV_CNT > KEY_CNT);
+
+	/*
+	 * Virtualization (VMware, etc) and remote management (HP
+	 * ILO2) solutions use absolute coordinates for their virtual
+	 * pointing devices so that there is one-to-one relationship
+	 * between pointer position on the host screen and virtual
+	 * guest screen, and so their mice use ABS_X, ABS_Y and 3
+	 * primary button events. This clashes with what joydev
+	 * considers to be joysticks (a device with at minimum ABS_X
+	 * axis).
+	 *
+	 * Here we are trying to separate absolute mice from
+	 * joysticks. A device is, for joystick detection purposes,
+	 * considered to be an absolute mouse if the following is
+	 * true:
+	 *
+	 * 1) Event types are exactly EV_ABS, EV_KEY and EV_SYN.
+	 * 2) Absolute events are exactly ABS_X and ABS_Y.
+	 * 3) Keys are exactly BTN_LEFT, BTN_RIGHT and BTN_MIDDLE.
+	 * 4) Device is not on "Amiga" bus.
+	 */
+
+	bitmap_zero(jd_scratch, EV_CNT);
+	__set_bit(EV_ABS, jd_scratch);
+	__set_bit(EV_KEY, jd_scratch);
+	__set_bit(EV_SYN, jd_scratch);
+	if (!bitmap_equal(jd_scratch, dev->evbit, EV_CNT))
+		return false;
+
+	bitmap_zero(jd_scratch, ABS_CNT);
+	__set_bit(ABS_X, jd_scratch);
+	__set_bit(ABS_Y, jd_scratch);
+	if (!bitmap_equal(dev->absbit, jd_scratch, ABS_CNT))
+		return false;
+
+	bitmap_zero(jd_scratch, KEY_CNT);
+	__set_bit(BTN_LEFT, jd_scratch);
+	__set_bit(BTN_RIGHT, jd_scratch);
+	__set_bit(BTN_MIDDLE, jd_scratch);
+
+	if (!bitmap_equal(dev->keybit, jd_scratch, KEY_CNT))
+		return false;
+
+	/*
+	 * Amiga joystick (amijoy) historically uses left/middle/right
+	 * button events.
+	 */
+	if (dev->id.bustype == BUS_AMIGA)
+		return false;
+
+	return true;
+}
 
 static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 {
@@ -758,6 +815,10 @@ static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
 	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
 		return false;
 
+	/* Avoid absolute mice */
+	if (joydev_dev_is_absolute_mouse(dev))
+		return false;
+
 	return true;
 }