[linux-usb-devel] [PATCH 4/5] USB: add Cypress c67x00 OTG controller HCD driver

[Alan Stern]

On Fri, 23 Nov 2007, Grant Likely wrote:

> From: Grant Likely <grant.likely at secretlab.ca>
> 
> This patch adds HDC support for the Cypress c67x00 family of devices.
> 
> Signed-off-by: Grant Likely <grant.likely at secretlab.ca>

> +static void c67x00_sched_done(unsigned long __c67x00)
> +{
> +	struct c67x00_hcd *c67x00 = (struct c67x00_hcd *)__c67x00;
> +	struct c67x00_urb_priv *urbp, *tmp;
> +	struct usb_hcd *hcd = c67x00_hcd_to_hcd(c67x00);
> +	struct urb *urb;
> +	int status;
> +
> +	spin_lock(&c67x00->lock);
> +
> +	/* Loop over the done list and give back all the urbs */
> +	list_for_each_entry_safe(urbp, tmp, &c67x00->done_list, hep_node) {
> +		urb = urbp->urb;
> +		status = urbp->status;
> +
> +		c67x00_release_urb(c67x00, urb);
> +
> +		usb_hcd_unlink_urb_from_ep(hcd, urb);
> +		usb_hcd_giveback_urb(hcd, urb, status);
> +	}
> +	spin_unlock(&c67x00->lock);
> +}

You need to release the spinlock around the call to 
usb_hcd_giveback_urb().  Otherwise you will deadlock if the completion 
routine submits another URB.

Alan Stern