From 5209dc65c1ff40a46187f5de27190a58f8d59be9 Mon Sep 17 00:00:00 2001
From: Pavel Rojtberg <rojtberg@gmail.com>
Date: Sun, 27 Sep 2015 23:43:09 +0200
Subject: [PATCH] Input: xpad: replace mutex by spinlock

since we cannot use mutexes in xpad_play_effect.
see: http://www.spinics.net/lists/linux-input/msg40242.html
---
 xpad.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/xpad.c b/xpad.c
index c5387b2..8fbe7b0 100644
--- a/xpad.c
+++ b/xpad.c
@@ -333,7 +333,7 @@ struct usb_xpad {
 	int irq_out_active;		/* we must not use an active URB */
 	unsigned char *odata;		/* output data */
 	dma_addr_t odata_dma;
-	struct mutex odata_mutex;
+	spinlock_t odata_lock;
 
 #if defined(CONFIG_JOYSTICK_XPAD_LEDS)
 	struct xpad_led *led;
@@ -751,7 +751,7 @@ static int xpad_init_output(struct usb_interface *intf, struct usb_xpad *xpad)
 		goto fail1;
 	}
 
-	mutex_init(&xpad->odata_mutex);
+	spin_lock_init(&xpad->odata_lock);
 
 	xpad->irq_out = usb_alloc_urb(0, GFP_KERNEL);
 	if (!xpad->irq_out) {
@@ -799,13 +799,15 @@ static int xpad_play_effect(struct input_dev *dev, void *data, struct ff_effect
 	__u16 weak;
 	int retval;
 
+	unsigned long flags;
+
 	if (effect->type != FF_RUMBLE)
 		return 0;
 
 	strong = effect->u.rumble.strong_magnitude;
 	weak = effect->u.rumble.weak_magnitude;
 
-	mutex_lock(&xpad->odata_mutex);
+	spin_lock_irqsave(&xpad->odata_lock, flags);
 
 	switch (xpad->xtype) {
 	case XTYPE_XBOX:
@@ -863,7 +865,7 @@ static int xpad_play_effect(struct input_dev *dev, void *data, struct ff_effect
 		break;
 
 	default:
-		mutex_unlock(&xpad->odata_mutex);
+		spin_unlock_irqrestore(&xpad->odata_lock, flags);
 		dev_dbg(&xpad->dev->dev,
 			"%s - rumble command sent to unsupported xpad type: %d\n",
 			__func__, xpad->xtype);
@@ -879,7 +881,7 @@ static int xpad_play_effect(struct input_dev *dev, void *data, struct ff_effect
 				__func__);
 	}
 
-	mutex_unlock(&xpad->odata_mutex);
+	spin_unlock_irqrestore(&xpad->odata_lock, flags);
 
 	return retval;
 }
@@ -929,9 +931,11 @@ struct xpad_led {
  */
 static void xpad_send_led_command(struct usb_xpad *xpad, int command)
 {
+	unsigned long flags;
+
 	command %= 16;
 
-	mutex_lock(&xpad->odata_mutex);
+	spin_lock_irqsave(&xpad->odata_lock, flags);
 
 	switch (xpad->xtype) {
 	case XTYPE_XBOX360:
@@ -964,7 +968,7 @@ static void xpad_send_led_command(struct usb_xpad *xpad, int command)
 		dev_dbg(&xpad->dev->dev, "%s - dropped, irq_out is active\n",
 				__func__);
 
-	mutex_unlock(&xpad->odata_mutex);
+	spin_unlock_irqrestore(&xpad->odata_lock, flags);
 }
 
 /*
@@ -1041,6 +1045,8 @@ static int xpad_open(struct input_dev *dev)
 	struct usb_xpad *xpad = input_get_drvdata(dev);
 	int retval;
 
+	unsigned long flags;
+
 	/* URB was submitted in probe */
 	if (xpad->xtype == XTYPE_XBOX360W)
 		return 0;
@@ -1050,13 +1056,13 @@ static int xpad_open(struct input_dev *dev)
 		return -EIO;
 
 	if (xpad->xtype == XTYPE_XBOXONE) {
-		mutex_lock(&xpad->odata_mutex);
+		spin_lock_irqsave(&xpad->odata_lock, flags);
 		/* Xbox one controller needs to be initialized. */
 		xpad->odata[0] = 0x05;
 		xpad->odata[1] = 0x20;
 		xpad->irq_out->transfer_buffer_length = 2;
 		retval = usb_submit_urb(xpad->irq_out, GFP_KERNEL);
-		mutex_unlock(&xpad->odata_mutex);
+		spin_unlock_irqrestore(&xpad->odata_lock, flags);
 		return retval;
 	}
 
@@ -1200,6 +1206,8 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
 	int ep_irq_in_idx;
 	int i, error;
 
+	unsigned long flags;
+
 	for (i = 0; xpad_device[i].idVendor; i++) {
 		if ((le16_to_cpu(udev->descriptor.idVendor) == xpad_device[i].idVendor) &&
 		    (le16_to_cpu(udev->descriptor.idProduct) == xpad_device[i].idProduct))
@@ -1301,7 +1309,7 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
 		 * adapter has been plugged in, as it won't automatically
 		 * send us info about the controllers.
 		 */
-		mutex_lock(&xpad->odata_mutex);
+		spin_lock_irqsave(&xpad->odata_lock, flags);
 		xpad->odata[0] = 0x08;
 		xpad->odata[1] = 0x00;
 		xpad->odata[2] = 0x0F;
@@ -1323,7 +1331,7 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
 			dev_dbg(&xpad->dev->dev,
 				"%s - dropped, irq_out is active\n", __func__);
 
-		mutex_unlock(&xpad->odata_mutex);
+		spin_unlock_irqrestore(&xpad->odata_lock, flags);
 	} else {
 		xpad->pad_present = 1;
 		error = xpad_init_input(xpad);