usb: dwc3: gadget: Fix BUG in RT config

Roger Quadros · Felipe Balbi · commit a66c275b3d5d · 2015-09-21T14:42:36.000-05:00
Using spin_lock() in hard irq handler is pointless
and causes a BUG() in RT (real-time) configuration
so get rid of it.

The reason it's pointless is because the driver is
basically accessing register which is, anyways,
atomic.

Signed-off-by: Roger Quadros &lt;rogerq@ti.com&gt;
Signed-off-by: Felipe Balbi &lt;balbi@ti.com&gt;
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
@@ -2665,8 +2665,6 @@ static irqreturn_t dwc3_interrupt(int irq, void *_dwc)
 	int				i;
 	irqreturn_t			ret = IRQ_NONE;
 
-	spin_lock(&dwc->lock);
-
 	for (i = 0; i < dwc->num_event_buffers; i++) {
 		irqreturn_t status;
 
@@ -2675,8 +2673,6 @@ static irqreturn_t dwc3_interrupt(int irq, void *_dwc)
 			ret = status;
 	}
 
-	spin_unlock(&dwc->lock);
-
 	return ret;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -2665,8 +2665,6 @@ static irqreturn_t dwc3_interrupt(int irq, void *_dwc)`
`2665`	`2665`	`int i;`
`2666`	`2666`	`irqreturn_t ret = IRQ_NONE;`
`2667`	`2667`
`2668`		`- spin_lock(&dwc->lock);`
`2669`		`-`
`2670`	`2668`	`for (i = 0; i < dwc->num_event_buffers; i++) {`
`2671`	`2669`	`irqreturn_t status;`
`2672`	`2670`
`@@ -2675,8 +2673,6 @@ static irqreturn_t dwc3_interrupt(int irq, void *_dwc)`
`2675`	`2673`	`ret = status;`
`2676`	`2674`	`}`
`2677`	`2675`
`2678`		`- spin_unlock(&dwc->lock);`
`2679`		`-`
`2680`	`2676`	`return ret;`
`2681`	`2677`	`}`
`2682`	`2678`