USB: musb: clear the Blackfin interrupt pending bits early in the ISR

If we clear the interrupt pending bits at the end, we sometimes return too
fast and have the same interrupt assert itself.  There is no way in a
Blackfin system to force a sync of this state, so the hardware manual
instructs people to clear interrupt flags early in their ISR.

Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/musbhsdma.c

@@ -259,6 +259,11 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data)
 	if (!int_hsdma)
 		goto done;
 
+#ifdef CONFIG_BLACKFIN
+	/* Clear DMA interrupt flags */
+	musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma);
+#endif
+
 	for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) {
 		if (int_hsdma & (1 << bchannel)) {
 			musb_channel = (struct musb_dma_channel *)
@@ -324,11 +329,6 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data)
 		}
 	}
 
-#ifdef CONFIG_BLACKFIN
-	/* Clear DMA interrup flags */
-	musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma);
-#endif
-
 	retval = IRQ_HANDLED;
 done:
 	spin_unlock_irqrestore(&musb->lock, flags);