USB: dummy-hcd: disable interrupts during req->complete

AlanStern · gregkh · commit b4dbda1a22d2 · 2006-08-02T16:41:42.000-07:00
This patch (as756) fixes a bug in dummy-hcd found by the lockdep
checker.  In one of the code paths, the driver did not disable
interrupts before calling a request completion routine.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
@@ -609,7 +609,8 @@ static int dummy_dequeue (struct usb_ep *_ep, struct usb_request *_req)
 	if (!dum->driver)
 		return -ESHUTDOWN;
 
-	spin_lock_irqsave (&dum->lock, flags);
+	local_irq_save (flags);
+	spin_lock (&dum->lock);
 	list_for_each_entry (req, &ep->queue, queue) {
 		if (&req->req == _req) {
 			list_del_init (&req->queue);
@@ -618,14 +619,15 @@ static int dummy_dequeue (struct usb_ep *_ep, struct usb_request *_req)
 			break;
 		}
 	}
-	spin_unlock_irqrestore (&dum->lock, flags);
+	spin_unlock (&dum->lock);
 
 	if (retval == 0) {
 		dev_dbg (udc_dev(dum),
 				"dequeued req %p from %s, len %d buf %p\n",
 				req, _ep->name, _req->length, _req->buf);
 		_req->complete (_ep, _req);
 	}
+	local_irq_restore (flags);
 	return retval;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -609,7 +609,8 @@ static int dummy_dequeue (struct usb_ep _ep, struct usb_request _req)`
`609`	`609`	`if (!dum->driver)`
`610`	`610`	`return -ESHUTDOWN;`
`611`	`611`
`612`		`- spin_lock_irqsave (&dum->lock, flags);`
	`612`	`+ local_irq_save (flags);`
	`613`	`+ spin_lock (&dum->lock);`
`613`	`614`	`list_for_each_entry (req, &ep->queue, queue) {`
`614`	`615`	`if (&req->req == _req) {`
`615`	`616`	`list_del_init (&req->queue);`
`@@ -618,14 +619,15 @@ static int dummy_dequeue (struct usb_ep _ep, struct usb_request _req)`
`618`	`619`	`break;`
`619`	`620`	`}`
`620`	`621`	`}`
`621`		`- spin_unlock_irqrestore (&dum->lock, flags);`
	`622`	`+ spin_unlock (&dum->lock);`
`622`	`623`
`623`	`624`	`if (retval == 0) {`
`624`	`625`	`dev_dbg (udc_dev(dum),`
`625`	`626`	`"dequeued req %p from %s, len %d buf %p\n",`
`626`	`627`	`req, _ep->name, _req->length, _req->buf);`
`627`	`628`	`_req->complete (_ep, _req);`
`628`	`629`	`}`
	`630`	`+ local_irq_restore (flags);`
`629`	`631`	`return retval;`
`630`	`632`	`}`
`631`	`633`