Subject: Re: [PATCH 1/6] drivers: usb: remove usage of list iterator past the loop body

From: Dan Carpenter <[email-masked]>
Date: Mon, 28 Feb 2022 14:24:13 +0300

On Mon, Feb 28, 2022 at 12:08:17PM +0100, Jakob Koschel wrote:
> diff --git a/drivers/usb/gadget/udc/at91_udc.c b/drivers/usb/gadget/udc/at91_udc.c
> index 9040a0561466..0fd0307bc07b 100644
> --- a/drivers/usb/gadget/udc/at91_udc.c
> +++ b/drivers/usb/gadget/udc/at91_udc.c
> @@ -150,13 +150,14 @@ static void proc_ep_show(struct seq_file *s, struct at91_ep *ep)
>  	if (list_empty (&ep->queue))
>  		seq_printf(s, "\t(queue empty)\n");
> 
> -	else list_for_each_entry (req, &ep->queue, queue) {
> -		unsigned	length = req->req.actual;
> +	else
> +		list_for_each_entry(req, &ep->queue, queue) {
> +			unsigned int	length = req->req.actual;
> 
> -		seq_printf(s, "\treq %p len %d/%d buf %p\n",
> -				&req->req, length,
> -				req->req.length, req->req.buf);
> -	}
> +			seq_printf(s, "\treq %p len %d/%d buf %p\n",
> +					&req->req, length,
> +					req->req.length, req->req.buf);
> +		}

Don't make unrelated white space changes.  It just makes the patch
harder to review.  As you're writing the patch make note of any
additional changes and do them later in a separate patch.

Also a multi-line indent gets curly braces for readability even though
it's not required by C.  And then both sides would get curly braces.

>  	spin_unlock_irqrestore(&udc->lock, flags);
>  }
> 
> @@ -226,7 +227,7 @@ static int proc_udc_show(struct seq_file *s, void *unused)
> 
>  	if (udc->enabled && udc->vbus) {
>  		proc_ep_show(s, &udc->ep[0]);
> -		list_for_each_entry (ep, &udc->gadget.ep_list, ep.ep_list) {
> +		list_for_each_entry(ep, &udc->gadget.ep_list, ep.ep_list) {

Another unrelated change.

>  			if (ep->ep.desc)
>  				proc_ep_show(s, ep);
>  		}

[ snip ]

> diff --git a/drivers/usb/gadget/udc/net2272.c b/drivers/usb/gadget/udc/net2272.c
> index 7c38057dcb4a..bb59200f1596 100644
> --- a/drivers/usb/gadget/udc/net2272.c
> +++ b/drivers/usb/gadget/udc/net2272.c
> @@ -926,7 +926,8 @@ static int
>  net2272_dequeue(struct usb_ep *_ep, struct usb_request *_req)
>  {
>  	struct net2272_ep *ep;
> -	struct net2272_request *req;
> +	struct net2272_request *req = NULL;
> +	struct net2272_request *tmp;
>  	unsigned long flags;
>  	int stopped;
> 
> @@ -939,11 +940,13 @@ net2272_dequeue(struct usb_ep *_ep, struct usb_request *_req)
>  	ep->stopped = 1;
> 
>  	/* make sure it's still queued on this endpoint */
> -	list_for_each_entry(req, &ep->queue, queue) {
> -		if (&req->req == _req)
> +	list_for_each_entry(tmp, &ep->queue, queue) {
> +		if (&tmp->req == _req) {
> +			req = tmp;
>  			break;
> +		}
>  	}
> -	if (&req->req != _req) {
> +	if (!req) {
>  		ep->stopped = stopped;
>  		spin_unlock_irqrestore(&ep->dev->lock, flags);
>  		return -EINVAL;
> @@ -954,7 +957,6 @@ net2272_dequeue(struct usb_ep *_ep, struct usb_request *_req)
>  		dev_dbg(ep->dev->dev, "unlink (%s) pio\n", _ep->name);
>  		net2272_done(ep, req, -ECONNRESET);
>  	}
> -	req = NULL;

Another unrelated change.  These are all good changes but send them as
separate patches.

>  	ep->stopped = stopped;
> 
>  	spin_unlock_irqrestore(&ep->dev->lock, flags);

regards,
dan carpenter