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: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
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97e133d54c
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9ada8c5820
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@ -555,6 +555,7 @@ printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
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size_t size; /* Amount of data in a TX request. */
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size_t bytes_copied = 0;
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struct usb_request *req;
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int value;
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DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
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@ -634,7 +635,11 @@ printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
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return -EAGAIN;
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}
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if (usb_ep_queue(dev->in_ep, req, GFP_ATOMIC)) {
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/* here, we unlock, and only unlock, to avoid deadlock. */
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spin_unlock(&dev->lock);
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value = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC);
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spin_lock(&dev->lock);
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if (value) {
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list_add(&req->list, &dev->tx_reqs);
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spin_unlock_irqrestore(&dev->lock, flags);
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mutex_unlock(&dev->lock_printer_io);
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