Re: [PATCH v2] usb: raw-gadget: return -EINVAL if no proper ep address available

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Mar 11, 2022 at 11:22:38AM +0800, Wei Ming Chen wrote:
> If we try to use raw_ioctl_ep_enable() for ep5in on a hardware that
> only support from ep1-ep4 for both in and out direction, it will return
> -EBUSY originally.
> 
> I think it will be more intuitive if we return -EINVAL, because -EBUSY
> sounds like ep5in is not available now, but might be available in the
> future.
> 
> Signed-off-by: Wei Ming Chen <jj251510319013@gmail.com>
> ---
>  drivers/usb/gadget/legacy/raw_gadget.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c
> index d86c3a36441e..e5707626c4d4 100644
> --- a/drivers/usb/gadget/legacy/raw_gadget.c
> +++ b/drivers/usb/gadget/legacy/raw_gadget.c
> @@ -758,6 +758,7 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
>  	unsigned long flags;
>  	struct usb_endpoint_descriptor *desc;
>  	struct raw_ep *ep;
> +	bool ep_props_matched = false;
>  
>  	desc = memdup_user((void __user *)value, sizeof(*desc));
>  	if (IS_ERR(desc))
> @@ -787,13 +788,14 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
>  
>  	for (i = 0; i < dev->eps_num; i++) {
>  		ep = &dev->eps[i];
> -		if (ep->state != STATE_EP_DISABLED)
> -			continue;
>  		if (ep->addr != usb_endpoint_num(desc) &&
>  				ep->addr != USB_RAW_EP_ADDR_ANY)
>  			continue;
>  		if (!usb_gadget_ep_match_desc(dev->gadget, ep->ep, desc, NULL))
>  			continue;
> +		ep_props_matched = true;
> +		if (ep->state != STATE_EP_DISABLED)
> +			continue;
>  		ep->ep->desc = desc;
>  		ret = usb_ep_enable(ep->ep);
>  		if (ret < 0) {
> @@ -815,8 +817,13 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
>  		goto out_unlock;
>  	}
>  
> -	dev_dbg(&dev->gadget->dev, "fail, no gadget endpoints available\n");
> -	ret = -EBUSY;
> +	if (!ep_props_matched) {
> +		dev_dbg(&dev->gadget->dev, "fail, bad endpoint descriptor\n");
> +		ret = -EINVAL;
> +	} else {
> +		dev_dbg(&dev->gadget->dev, "fail, no endpoints available\n");
> +		ret = -EBUSY;
> +	}
>  
>  out_free:
>  	kfree(desc);
> -- 
> 2.25.1
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/SubmittingPatches for what needs to be done
  here to properly describe this.

If you wish to discuss this problem further, or you have questions about
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Greg will reply once he has dug out from the pending patches received
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thanks,

greg k-h's patch email bot