HID: nintendo: reduce device removal subcommand errors

This patch fixes meaningless error output from trying to send
subcommands immediately after controller removal. It now disables
subcommands as soon as possible on removal.
Signed-off-by: Daniel J. Ogorchock <djogorchock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-nintendo.c

@@ -230,6 +230,7 @@ static const struct joycon_rumble_amp_data joycon_rumble_amplitudes[] = {
 enum joycon_ctlr_state {
 	JOYCON_CTLR_STATE_INIT,
 	JOYCON_CTLR_STATE_READ,
+	JOYCON_CTLR_STATE_REMOVED,
 };
 
 struct joycon_stick_cal {
@@ -458,6 +459,14 @@ static int joycon_send_subcmd(struct joycon_ctlr *ctlr,
 	unsigned long flags;
 
 	spin_lock_irqsave(&ctlr->lock, flags);
+	/*
+	 * If the controller has been removed, just return ENODEV so the LED
+	 * subsystem doesn't print invalid errors on removal.
+	 */
+	if (ctlr->ctlr_state == JOYCON_CTLR_STATE_REMOVED) {
+		spin_unlock_irqrestore(&ctlr->lock, flags);
+		return -ENODEV;
+	}
 	memcpy(subcmd->rumble_data, ctlr->rumble_data[ctlr->rumble_queue_tail],
 	       JC_RUMBLE_DATA_SIZE);
 	spin_unlock_irqrestore(&ctlr->lock, flags);
@@ -807,10 +816,13 @@ static void joycon_rumble_worker(struct work_struct *work)
 		mutex_lock(&ctlr->output_mutex);
 		ret = joycon_enable_rumble(ctlr);
 		mutex_unlock(&ctlr->output_mutex);
-		if (ret < 0)
-			hid_warn(ctlr->hdev, "Failed to set rumble; e=%d", ret);
 
+		/* -ENODEV means the controller was just unplugged */
 		spin_lock_irqsave(&ctlr->lock, flags);
+		if (ret < 0 && ret != -ENODEV &&
+		    ctlr->ctlr_state != JOYCON_CTLR_STATE_REMOVED)
+			hid_warn(ctlr->hdev, "Failed to set rumble; e=%d", ret);
+
 		ctlr->rumble_msecs = jiffies_to_msecs(jiffies);
 		if (ctlr->rumble_queue_tail != ctlr->rumble_queue_head) {
 			if (++ctlr->rumble_queue_tail >= JC_RUMBLE_QUEUE_SIZE)
@@ -1529,9 +1541,17 @@ static int nintendo_hid_probe(struct hid_device *hdev,
 static void nintendo_hid_remove(struct hid_device *hdev)
 {
 	struct joycon_ctlr *ctlr = hid_get_drvdata(hdev);
+	unsigned long flags;
 
 	hid_dbg(hdev, "remove\n");
+
+	/* Prevent further attempts at sending subcommands. */
+	spin_lock_irqsave(&ctlr->lock, flags);
+	ctlr->ctlr_state = JOYCON_CTLR_STATE_REMOVED;
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+
 	destroy_workqueue(ctlr->rumble_queue);
+
 	hid_hw_close(hdev);
 	hid_hw_stop(hdev);
 }