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authorThomas Hellstrom <thellstrom@vmware.com>2015-05-20 14:50:30 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2015-05-21 15:58:27 -0700
commit15397f153cfd69c2164c1fa593e26707ed1a3e72 (patch)
treee50c1163a187d0e15ec600c9af211a1c902f21ae /drivers
parent412dbad2c7e273b48e8477247c74b2ad65c452d2 (diff)
Input: joydev - don't classify the vmmouse as a joystick
Joydev is currently thinking some absolute mice are joystick, and that messes up games in VMware guests, as the cursor typically gets stuck in the top left corner. Try to detect the event signature of a VMmouse input device and back off for such devices. We're still incorrectly detecting, for example, the VMware absolute USB mouse as a joystick, but adding an event signature matching also that device would be considerably more risky, so defer that to a later merge window. Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/input/joydev.c61
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;
}

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