[PATCH evdev 2/8] num_slots should take into account the .mtdev field

[Benjamin Tissoires]

The current implementation assume that multitouch devices following the
Multitouch Protocol A (those requiring mtdev) present 10 touches,
no matter mtdev decides.
num_slots should be relying on mtdev when it is available.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires at gmail.com>
---
 src/evdev.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/evdev.c b/src/evdev.c
index 27b0e76..93758fd 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -755,8 +755,14 @@ EvdevProcessTouch(InputInfoPtr pInfo)
 static int
 num_slots(EvdevPtr pEvdev)
 {
-    int value = pEvdev->absinfo[ABS_MT_SLOT].maximum -
+    int value = 0;
+
+    if (!pEvdev->mtdev)
+        value = pEvdev->absinfo[ABS_MT_SLOT].maximum -
                 pEvdev->absinfo[ABS_MT_SLOT].minimum + 1;
+    else if (pEvdev->mtdev->caps.slot.maximum > 0)
+        value = pEvdev->mtdev->caps.slot.maximum -
+                pEvdev->mtdev->caps.slot.minimum + 1;
 
     /* If we don't know how many slots there are, assume at least 10 */
     return value > 1 ? value : 10;
@@ -1385,14 +1391,10 @@ EvdevAddAbsValuatorClass(DeviceIntPtr device)
 #ifdef MULTITOUCH
     if (pEvdev->mtdev && num_mt_axes_total > 0)
     {
-        int num_touches = 0;
+        int num_touches = num_slots(pEvdev);
         int mode = pEvdev->flags & EVDEV_TOUCHPAD ?
             XIDependentTouch : XIDirectTouch;
 
-        if (pEvdev->mtdev->caps.slot.maximum > 0)
-            num_touches = pEvdev->mtdev->caps.slot.maximum -
-                          pEvdev->mtdev->caps.slot.minimum + 1;
-
         if (!InitTouchClassDeviceStruct(device, num_touches, mode,
                                         num_mt_axes_total)) {
             xf86Msg(X_ERROR, "%s: failed to initialize touch class device.\n",
-- 
1.8.0.2