Re: [PATCH v2] usb: udc: core: Use lock when write to soft_connect

Andy Shevchenko wrote:

On Thursday, January 14, 2021, Ahmed S. Darwish <a.darwish@linutronix.de mailto:a.darwish@linutronix.de> wrote:

On Wed, Jan 13, 2021 at 07:38:28PM -0800, Thinh Nguyen wrote:
...
> @@ -1543,10 +1546,12 @@ static ssize_t soft_connect_store(struct
device *dev,
>               usb_gadget_udc_stop(udc);
>       } else {
>               dev_err(dev, "unsupported command '%s'\n", buf);
> -             return -EINVAL;
> +             ret = -EINVAL;
>       }
>
> -     return n;

Should be ret = n; here.

> +out:
> +     mutex_unlock(&udc_lock);
> +     return ret;
>  }

This is *very* tricky: the return value will be easily broken if
someone
adds any code later after the else body and before the "out" label.

+1 and it’s not good pattern to assign return value at the definition time (see comment above ).

-- With Best Regards, Andy Shevchenko

Good point. I didn't think about that. Thanks guys.

Thinh