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Commit 9ada8c58 authored by Yoshihiro Shimoda's avatar Yoshihiro Shimoda Committed by Felipe Balbi
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usb: gadget: function: printer: avoid spinlock recursion 



If usb_gadget_giveback_request() is called in usb_ep_queue(),
this printer_write() is possible to cause spinlock recursion. So,
this patch adds spin_unlock() before calls usb_ep_queue() to avoid it.

Signed-off-by: default avatarYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 97e133d5

drivers/usb/gadget/function/f_printer.c

+6 −1
Original line number Diff line number Diff line
@@ -555,6 +555,7 @@ printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 
	size_t			size;	/* Amount of data in a TX request. */

	size_t			bytes_copied = 0;

	struct usb_request	*req;

	int			value;



	DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
@@ -634,7 +635,11 @@ printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr) 
			return -EAGAIN;

		}



		if (usb_ep_queue(dev->in_ep, req, GFP_ATOMIC)) {

		/* here, we unlock, and only unlock, to avoid deadlock. */

		spin_unlock(&dev->lock);

		value = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC);

		spin_lock(&dev->lock);

		if (value) {

			list_add(&req->list, &dev->tx_reqs);

			spin_unlock_irqrestore(&dev->lock, flags);

			mutex_unlock(&dev->lock_printer_io);