media: rc: xbox_remote: heed DMA restrictions

commit e280d1e upstream.

The buffer for IO must not be part of the device structure
because that violates the DMA coherency rules.

Fixes: 02d32bd ("media: rc: add driver for Xbox DVD Movie Playback Kit")
Cc: stable@vger.kernel.org
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: oneukum

drivers/media/rc/xbox_remote.c

@@ -55,7 +55,7 @@ struct xbox_remote {
 	struct usb_interface *interface;
 
 	struct urb *irq_urb;
-	unsigned char inbuf[DATA_BUFSIZE] __aligned(sizeof(u16));
+	u8 *inbuf;
 
 	char rc_name[NAME_BUFSIZE];
 	char rc_phys[NAME_BUFSIZE];
@@ -218,6 +218,10 @@ static int xbox_remote_probe(struct usb_interface *interface,
 	if (!xbox_remote || !rc_dev)
 		goto exit_free_dev_rdev;
 
+	xbox_remote->inbuf = kzalloc(DATA_BUFSIZE, GFP_KERNEL);
+	if (!xbox_remote->inbuf)
+		goto exit_free_inbuf;
+
 	/* Allocate URB buffer */
 	xbox_remote->irq_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!xbox_remote->irq_urb)
@@ -262,6 +266,8 @@ static int xbox_remote_probe(struct usb_interface *interface,
 	usb_kill_urb(xbox_remote->irq_urb);
 exit_free_buffers:
 	usb_free_urb(xbox_remote->irq_urb);
+exit_free_inbuf:
+	kfree(xbox_remote->inbuf);
 exit_free_dev_rdev:
 	rc_free_device(rc_dev);
 	kfree(xbox_remote);
@@ -286,6 +292,7 @@ static void xbox_remote_disconnect(struct usb_interface *interface)
 	usb_kill_urb(xbox_remote->irq_urb);
 	rc_unregister_device(xbox_remote->rdev);
 	usb_free_urb(xbox_remote->irq_urb);
+	kfree(xbox_remote->inbuf);
 	kfree(xbox_remote);
 }