[PATCH v2 02/10] Input - wacom: put a flag when the led are initialized

From: Benjamin Tissoires
Date: Thu Jul 24 2014 - 14:14:45 EST


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@xxxxxxxxxx>
Acked-by: Ping Cheng <pingc@xxxxxxxxx>
---

no changes in v2

drivers/hid/wacom.h | 1 +
drivers/hid/wacom_sys.c | 6 ++++++
2 files changed, 7 insertions(+)

diff --git a/drivers/hid/wacom.h b/drivers/hid/wacom.h
index dd67b7d..a678f82 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 9dbb6dd..c857b3d 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:
--
2.0.1

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