Re: [PATCH 26/26] usb: gadget: udc: s3c2410: replace usage of rc to check if a list element was found

From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
To: Jakob Koschel <jakobkoschel@gmail.com>,
	Greg Kroah-Hartman <greg@kroah.com>
Cc: linux-kernel@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Felipe Balbi <balbi@kernel.org>, Joel Stanley <joel@jms.id.au>,
	Andrew Jeffery <andrew@aj.id.au>,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Claudiu Beznea <claudiu.beznea@microchip.com>,
	Cristian Birsan <cristian.birsan@microchip.com>,
	Al Cooper <alcooperx@gmail.com>, Li Yang <leoyang.li@nxp.com>,
	Vladimir Zapolskiy <vz@mleia.com>,
	Daniel Mack <daniel@zonque.org>,
	Haojian Zhuang <haojian.zhuang@gmail.com>,
	Robert Jarzmik <robert.jarzmik@free.fr>,
	Alim Akhtar <alim.akhtar@samsung.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Michal Simek <michal.simek@xilinx.com>,
	"open list:USB GADGET/PERIPHERAL SUBSYSTEM" 
	<linux-usb@vger.kernel.org>, Mike Rapoport <rppt@kernel.org>,
	Brian Johannesmeyer <bjohannesmeyer@gmail.com>,
	Cristiano Giuffrida <c.giuffrida@vu.nl>,
	"Bos, H.J." <h.j.bos@vu.nl>
Subject: Re: [PATCH 26/26] usb: gadget: udc: s3c2410: replace usage of rc to check if a list element was found
Date: Mon, 7 Mar 2022 13:13:44 +0100	[thread overview]
Message-ID: <3655d921-3798-0a01-1b7a-32261389dde5@canonical.com> (raw)
In-Reply-To: <20220306175034.3084609-27-jakobkoschel@gmail.com>

On 06/03/2022 18:50, Jakob Koschel wrote:
> To move the list iterator variable into the list_for_each_entry_*()
> macro in the future it should be avoided to use the list iterator
> variable after the loop body.
> 
> To *never* use the list iterator variable after the loop it was
> concluded to use a separate iterator variable [1].
> 
> This removes the need to check the rc value to determine if the
> break/goto was hit and can be made more obvious
> by checking if the variable was set within the list traversal loop.
> 
> Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/
> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
> ---
>  drivers/usb/gadget/udc/s3c2410_udc.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/s3c2410_udc.c b/drivers/usb/gadget/udc/s3c2410_udc.c
> index e3931da24277..fe6ecb0d16d1 100644
> --- a/drivers/usb/gadget/udc/s3c2410_udc.c
> +++ b/drivers/usb/gadget/udc/s3c2410_udc.c
> @@ -1265,7 +1265,7 @@ static int s3c2410_udc_dequeue(struct usb_ep *_ep, struct usb_request *_req)
>  	struct s3c2410_ep	*ep = to_s3c2410_ep(_ep);
>  	int			retval = -EINVAL;
>  	unsigned long		flags;
> -	struct s3c2410_request	*req = NULL;
> +	struct s3c2410_request	*req = NULL, *tmp;
>  
>  	dprintk(DEBUG_VERBOSE, "%s(%p,%p)\n", __func__, _ep, _req);
>  
> @@ -1277,16 +1277,17 @@ static int s3c2410_udc_dequeue(struct usb_ep *_ep, struct usb_request *_req)
>  
>  	local_irq_save(flags);
>  
> -	list_for_each_entry(req, &ep->queue, queue) {
> -		if (&req->req == _req) {
> -			list_del_init(&req->queue);
> +	list_for_each_entry(tmp, &ep->queue, queue) {
> +		if (&tmp->req == _req) {
> +			list_del_init(&tmp->queue);
>  			_req->status = -ECONNRESET;
> +			req = tmp;
>  			retval = 0;
>  			break;
>  		}
>  	}
>  
> -	if (retval == 0) {
> +	if (req) {

I saw comments from Greg about it, so please keep similar approach here
as in patch 25. I propose to keep retval.

With retval restored:
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Best regards,
Krzysztof