len and remain can never be negative in gdm_tty_write(). So remove such
a check and move the check of remaining bytes to the loop condition.
This way, the preceding 'if' is now superfluous too. Fix all that and
make the code cleaner.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: linux-staging@lists.linux.dev
---
 drivers/staging/gdm724x/gdm_tty.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/staging/gdm724x/gdm_tty.c b/drivers/staging/gdm724x/gdm_tty.c
index cbaaa8fa7474..67d9bf41e836 100644
--- a/drivers/staging/gdm724x/gdm_tty.c
+++ b/drivers/staging/gdm724x/gdm_tty.c
@@ -158,10 +158,7 @@ static ssize_t gdm_tty_write(struct tty_struct *tty, const u8 *buf, size_t len)
 	if (!gdm_tty_ready(gdm))
 		return -ENODEV;
 
-	if (!len)
-		return 0;
-
-	while (1) {
+	while (remain) {
 		size_t sending_len = min(MUX_TX_MAX_SIZE, remain);
 		gdm->tty_dev->send_func(gdm->tty_dev->priv_dev,
 					(void *)(buf + sent_len),
@@ -171,8 +168,6 @@ static ssize_t gdm_tty_write(struct tty_struct *tty, const u8 *buf, size_t len)
 					gdm);
 		sent_len += sending_len;
 		remain -= sending_len;
-		if (remain <= 0)
-			break;
 	}
 
 	return len;
-- 
2.41.0

On Thu, 10 Aug 2023, Jiri Slaby (SUSE) wrote:

> len and remain can never be negative in gdm_tty_write(). So remove such
> a check and move the check of remaining bytes to the loop condition.
> This way, the preceding 'if' is now superfluous too. Fix all that and
> make the code cleaner.
> 
> Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>

I guess Suggested-by would be more appropriate since there's no problem 
being fixed here.

> Cc: linux-staging@lists.linux.dev

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

-- 
 i.



> ---
>  drivers/staging/gdm724x/gdm_tty.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/drivers/staging/gdm724x/gdm_tty.c b/drivers/staging/gdm724x/gdm_tty.c
> index cbaaa8fa7474..67d9bf41e836 100644
> --- a/drivers/staging/gdm724x/gdm_tty.c
> +++ b/drivers/staging/gdm724x/gdm_tty.c
> @@ -158,10 +158,7 @@ static ssize_t gdm_tty_write(struct tty_struct *tty, const u8 *buf, size_t len)
>  	if (!gdm_tty_ready(gdm))
>  		return -ENODEV;
>  
> -	if (!len)
> -		return 0;
> -
> -	while (1) {
> +	while (remain) {
>  		size_t sending_len = min(MUX_TX_MAX_SIZE, remain);
>  		gdm->tty_dev->send_func(gdm->tty_dev->priv_dev,
>  					(void *)(buf + sent_len),
> @@ -171,8 +168,6 @@ static ssize_t gdm_tty_write(struct tty_struct *tty, const u8 *buf, size_t len)
>  					gdm);
>  		sent_len += sending_len;
>  		remain -= sending_len;
> -		if (remain <= 0)
> -			break;
>  	}
>  
>  	return len;
>