Re: [PATCH 1/2] drivers: usb: gadget: udc: add missing break in switch

Michal Nazarewicz
2017-02-08T13:20:09Z

On Wed, Feb 08 2017, Felipe Balbi wrote:
> Hi,
>
> "Gustavo A. R. Silva" <garsilva@embeddedor.com> writes:
>> Add missing break in switch.
>>
>> Addresses-Coverity-ID: 201385
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>> ---
>> drivers/usb/gadget/udc/mv_udc_core.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/usb/gadget/udc/mv_udc_core.c b/drivers/usb/gadget/udc/mv_udc_core.c
>> index 27ebb0d..56b3574 100644
>> --- a/drivers/usb/gadget/udc/mv_udc_core.c
>> +++ b/drivers/usb/gadget/udc/mv_udc_core.c
>> @@ -489,6 +489,7 @@ static int mv_ep_enable(struct usb_ep *_ep,
>> break;
>> case USB_ENDPOINT_XFER_CONTROL:
>> ios = 1;
>> + break;
>
> are you SURE this is supposed to have this break statement? What if we
> want to initialize mult to 0 *also* for control endpoints? How did you
> test this? Do you have access to Marvel's documentation for this
> controller?

Actually it doesn’t matter. mult is initialised to zero when it’s
declared and then not touched before the switch.

To improve readability, maybe something like:

---- >8 ------------------------------------------------------------
diff --git a/drivers/usb/gadget/udc/mv_udc_core.c b/drivers/usb/gadget/udc/mv_udc_core.c
index d82a91bddbd9..7440c9f92ec1 100644
--- a/drivers/usb/gadget/udc/mv_udc_core.c
+++ b/drivers/usb/gadget/udc/mv_udc_core.c
@@ -445,7 +445,8 @@ static int mv_ep_enable(struct usb_ep *_ep,
struct mv_dqh *dqh;
u16 max = 0;
u32 bit_pos, epctrlx, direction;
- unsigned char zlt = 0, ios = 0, mult = 0;
+ const unsigned char zlt = 1;
+ unsigned char ios, mult;
unsigned long flags;

ep = container_of(_ep, struct mv_ep, ep);
@@ -465,8 +466,6 @@ static int mv_ep_enable(struct usb_ep *_ep,
* disable HW zero length termination select
* driver handles zero length packet through req->req.zero
*/
- zlt = 1;
-
bit_pos = 1 << ((direction == EP_DIR_OUT ? 0 : 16) + ep->ep_num);

/* Check if the Endpoint is Primed */
@@ -481,16 +480,16 @@ static int mv_ep_enable(struct usb_ep *_ep,
(unsigned)bit_pos);
goto en_done;
}
+
/* Set the max packet length, interrupt on Setup and Mult fields */
+ ios = 0;
+ mult = 0;
switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
case USB_ENDPOINT_XFER_BULK:
- zlt = 1;
- mult = 0;
+ case USB_ENDPOINT_XFER_INT:
break;
case USB_ENDPOINT_XFER_CONTROL:
ios = 1;
- case USB_ENDPOINT_XFER_INT:
- mult = 0;
break;
case USB_ENDPOINT_XFER_ISOC:
/* Calculate transactions needed for high bandwidth iso */
---- >8 ------------------------------------------------------------

--
Best regards
ミハウ “𝓶𝓲𝓷𝓪86” ナザレヴイツ
«If at first you don’t succeed, give up skydiving»