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Subject: Re: [PATCH v2] media: pvrusb2: fix parsing error
To:     Tong Zhang <ztong0001@gmail.com>, isely@pobox.com,
        mchehab@kernel.org, linux-media@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <75b8354b-362a-0215-8038-45bd68be7de5@xs4all.nl>
 <20200819212523.113973-1-ztong0001@gmail.com>
From:   Hans Verkuil <hverkuil@xs4all.nl>
Message-ID: <aed971ed-bd8e-eaed-b2ee-80e9654f24cd@xs4all.nl>
Date:   Thu, 20 Aug 2020 13:44:44 +0200
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On 19/08/2020 23:25, Tong Zhang wrote:
> pvr2_std_str_to_id() returns 0 on failure and 1 on success,
> however the caller is checking failure case using <0
> 
> Co-developed-by: Hans Verkuil<hverkuil@xs4all.nl>
> Signed-off-by: Tong Zhang <ztong0001@gmail.com>
> ---
> 
> v2: return -EINVAL as suggested by Hans Verkuil<hverkuil@xs4all.nl>.
> I also rebased the code on v5.9-rc1.
> 
>  drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
> index 1cfb7cf64131..6a444cb27e31 100644
> --- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
> +++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
> @@ -866,8 +866,8 @@ static int ctrl_std_sym_to_val(struct pvr2_ctrl *cptr,
>  {
>  	int ret;

This is no longer used, so can be removed.

And if I compile this patch I get this warning:

drivers/media/usb/pvrusb2/pvrusb2-hdw.c: In function ‘ctrl_std_sym_to_val’:
drivers/media/usb/pvrusb2/pvrusb2-hdw.c:867:6: warning: unused variable ‘ret’ [-Wunused-variable]
  867 |  int ret;
      |      ^~~

Always compile-test before posting a patch :-)

Regards,

	Hans

>  	v4l2_std_id id;
> -	ret = pvr2_std_str_to_id(&id,bufPtr,bufSize);
> -	if (ret < 0) return ret;
> +	if (!pvr2_std_str_to_id(&id, bufPtr, bufSize))
> +		return -EINVAL;
>  	if (mskp) *mskp = id;
>  	if (valp) *valp = id;
>  	return 0;
>