Input: wacom - put a flag when the led are initialized

This solves a bug with the wireless receiver:
- at plug, the wireless receiver does not know which Wacom device it is
  connected to, so it does not actually creates all the LEDs
- when the tablet connects, wacom->wacom_wac.features.type is set to the
  proper device so that wacom_wac can understand the packets
- when the receiver is unplugged, it detects that a LED should have been
  created (based on wacom->wacom_wac.features.type) and tries to remove
  it: crash when removing the sysfs group.

Side effect, we can now safely call several times wacom_destroy_leds().

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/drivers/hid/wacom.h b/drivers/hid/wacom.h
index dd67b7da8a97..a678f827e39e 100644
--- a/drivers/hid/wacom.h
+++ b/drivers/hid/wacom.h
@@ -118,6 +118,7 @@ struct wacom {
                 u8 hlv;       /* status led brightness button pressed (1..127) */
                 u8 img_lum;   /* OLED matrix display brightness */
         } led;
+        bool led_initialized;
         struct power_supply battery;
 };
 
diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 06e304b3bbfd..f1c6d3dae248 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -729,12 +729,18 @@ static int wacom_initialize_leds(struct wacom *wacom)
                 return error;
         }
         wacom_led_control(wacom);
+        wacom->led_initialized = true;
 
         return 0;
 }
 
 static void wacom_destroy_leds(struct wacom *wacom)
 {
+        if (!wacom->led_initialized)
+                return;
+
+        wacom->led_initialized = false;
+
         switch (wacom->wacom_wac.features.type) {
         case INTUOS4S:
         case INTUOS4: