If the function usb_maxpacket(urb->dev, urb->pipe, usb_pipeout(urb->pipe)) returns 0, that will cause a illegal divide-by-zero operation, unexpected results may occur.
It is best to ensure that the denominator is non-zero before dividing by zero.
Signed-off-by: Yanlin Du <duyanlin@xxxxxxxxxx>
---
drivers/usb/host/imx21-hcd.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/host/imx21-hcd.c b/drivers/usb/host/imx21-hcd.c index 6e3dad1..6a47f78 100644
--- a/drivers/usb/host/imx21-hcd.c
+++ b/drivers/usb/host/imx21-hcd.c
@@ -1038,6 +1038,7 @@ static void nonisoc_etd_done(struct usb_hcd *hcd, int etd_num)
int cc;
u32 bytes_xfrd;
int etd_done;
+ unsigned int maxp;
disactivate_etd(imx21, etd_num);
@@ -1104,13 +1105,13 @@ static void nonisoc_etd_done(struct usb_hcd *hcd, int etd_num)
break;
case PIPE_BULK:
+ maxp = usb_maxpacket(urb->dev, urb->pipe,
+ usb_pipeout(urb->pipe));
urb->actual_length += bytes_xfrd;
if ((urb_priv->state == US_BULK)
&& (urb->transfer_flags & URB_ZERO_PACKET)
&& urb->transfer_buffer_length > 0
- && ((urb->transfer_buffer_length %
- usb_maxpacket(urb->dev, urb->pipe,
- usb_pipeout(urb->pipe))) == 0)) {
+ && maxp && (urb->transfer_buffer_length % maxp == 0)) {
/* need a 0-packet */
urb_priv->state = US_BULK0;
} else {
--
1.8.5.6
