2022-03-07 03:37:29

by Jakob Koschel

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

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/[email protected]/
Signed-off-by: Jakob Koschel <[email protected]>
---
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) {
dprintk(DEBUG_VERBOSE,
"dequeued req %p from %s, len %d buf %p\n",
req, _ep->name, _req->length, _req->buf);
--
2.25.1

2022-03-08 09:20:42

by Krzysztof Kozlowski

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

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/[email protected]/
> Signed-off-by: Jakob Koschel <[email protected]>
> ---
> 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 <[email protected]>

Best regards,
Krzysztof