usb: dwc3: otg: Fix boot hang in RT config

Roger Quadros · nsekhar · commit 48a870a3faf9 · 2015-09-30T15:59:12.000+05:30
Using spin_lock() in hard irq handler is pointless
and causes a BUG() in RT (real-time) configuration
so get rid of it.

Acked-by: Felipe Balbi &lt;balbi@ti.com&gt;
Signed-off-by: Roger Quadros &lt;rogerq@ti.com&gt;
Signed-off-by: Sekhar Nori &lt;nsekhar@ti.com&gt;
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
@@ -806,8 +806,6 @@ static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
 	irqreturn_t ret = IRQ_NONE;
 	u32 reg;
 
-	spin_lock(&dwc->lock);
-
 	reg = dwc3_readl(dwc->regs, DWC3_OEVT);
 	if (reg) {
 		dwc->oevt = reg;
@@ -816,8 +814,6 @@ static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)
 		ret = IRQ_WAKE_THREAD;
 	}
 
-	spin_unlock(&dwc->lock);
-
 	return ret;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -806,8 +806,6 @@ static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)`
`806`	`806`	`irqreturn_t ret = IRQ_NONE;`
`807`	`807`	`u32 reg;`
`808`	`808`
`809`		`- spin_lock(&dwc->lock);`
`810`		`-`
`811`	`809`	`reg = dwc3_readl(dwc->regs, DWC3_OEVT);`
`812`	`810`	`if (reg) {`
`813`	`811`	`dwc->oevt = reg;`
`@@ -816,8 +814,6 @@ static irqreturn_t dwc3_otg_irq(int irq, void *_dwc)`
`816`	`814`	`ret = IRQ_WAKE_THREAD;`
`817`	`815`	`}`
`818`	`816`
`819`		`- spin_unlock(&dwc->lock);`
`820`		`-`
`821`	`817`	`return ret;`
`822`	`818`	`}`
`823`	`819`