HID: apple: avoid setting up battery timer for devices without battery

commit c061046 upstream.

Currently, the battery timer is set up for all devices using hid-apple,
irrespective of whether they actually have a battery or not.

APPLE_RDESC_BATTERY is a quirk that indicates the device has a battery
and needs the battery timer. This patch checks for this quirk before
setting up the timer, ensuring that only devices with a battery will
have the timer set up.

Fixes: 6e14329 ("HID: apple: Report Magic Keyboard battery over USB")
Cc: stable@vger.kernel.org
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hid/hid-apple.c

@@ -934,10 +934,12 @@ static int apple_probe(struct hid_device *hdev,
 		return ret;
 	}
 
-	timer_setup(&asc->battery_timer, apple_battery_timer_tick, 0);
-	mod_timer(&asc->battery_timer,
-		  jiffies + msecs_to_jiffies(APPLE_BATTERY_TIMEOUT_MS));
-	apple_fetch_battery(hdev);
+	if (quirks & APPLE_RDESC_BATTERY) {
+		timer_setup(&asc->battery_timer, apple_battery_timer_tick, 0);
+		mod_timer(&asc->battery_timer,
+			  jiffies + msecs_to_jiffies(APPLE_BATTERY_TIMEOUT_MS));
+		apple_fetch_battery(hdev);
+	}
 
 	if (quirks & APPLE_BACKLIGHT_CTL)
 		apple_backlight_init(hdev);
@@ -951,7 +953,9 @@ static int apple_probe(struct hid_device *hdev,
 	return 0;
 
 out_err:
-	timer_delete_sync(&asc->battery_timer);
+	if (quirks & APPLE_RDESC_BATTERY)
+		timer_delete_sync(&asc->battery_timer);
+
 	hid_hw_stop(hdev);
 	return ret;
 }
@@ -960,7 +964,8 @@ static void apple_remove(struct hid_device *hdev)
 {
 	struct apple_sc *asc = hid_get_drvdata(hdev);
 
-	timer_delete_sync(&asc->battery_timer);
+	if (asc->quirks & APPLE_RDESC_BATTERY)
+		timer_delete_sync(&asc->battery_timer);
 
 	hid_hw_stop(hdev);
 }