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

From: Felipe Balbi
Date: Wed Feb 08 2017 - 08:14:59 EST



Hi,

Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> writes:
> On Wed, Feb 08, 2017 at 02:05:35PM +0200, Felipe Balbi wrote:
>>
>> Hi,
>>
>> "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx> writes:
>> >> "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx> writes:
>> >>> Add missing break in switch.
>> >>>
>> >>> Addresses-Coverity-ID: 201385
>> >>> Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
>> >>> ---
>> >>> 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?
>> >>
>> >
>> > Certainly I wasn't sure, but I also think this is kind of obscure
>> > code. If that is the case that we also want to initialize mult to 0,
>> > wouldn't it be clearer (for maintenance purposes) to add mult = 0 and
>> > the break statement after ios = 1?
>> >
>> > What do you think if I modify that piece of code as follows:
>>
>> I think you need to test it, or get someone to test it for you :-)
>
> For crap code like this where it's "obvious" that something is wrong?
> That's really hard.

heh :-)

> How about a nice comment instead:
> /* Code path falls through, is it correct or not, who knows??? */
> which will make the static code checkers stop complaining about it, and
> if someone actually has the hardware, then they can test it.

works for me

--
balbi

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