usb: musb: check for zero byte in musb_read/write_fifo

Added a check in musb_{read | write}_fifo for zero byte length.

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 26f1bef..69711e4 100644 (file)
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -234,6 +234,9 @@ void musb_write_fifo(struct musb_hw_ep *hw_ep, u16 len, const u8 *src)
        struct musb *musb = hw_ep->musb;
        void __iomem *fifo = hw_ep->fifo;
 
+       if (unlikely(len == 0))
+               return;
+
        prefetch((u8 *)src);
 
        dev_dbg(musb->controller, "%cX ep%d fifo %p count %d buf %p\n",
@@ -276,6 +279,9 @@ void musb_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
        struct musb *musb = hw_ep->musb;
        void __iomem *fifo = hw_ep->fifo;
 
+       if (unlikely(len == 0))
+               return;
+
        dev_dbg(musb->controller, "%cX ep%d fifo %p count %d buf %p\n",
                        'R', hw_ep->epnum, fifo, len, dst);