Re: [PATCH v3 1/2] staging: vt6655: remove unnecessary volatile qualifier

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Sep 09, 2022 at 02:17:55PM +0200, Nam Cao wrote:
> Remove volatile qualifier for the member rd0 of struct vnt_rx_desc,
> because there is no reason it must be volatile.
> 
> Signed-off-by: Nam Cao <namcaov@gmail.com>
> ---
>  drivers/staging/vt6655/desc.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/vt6655/desc.h b/drivers/staging/vt6655/desc.h
> index 17a40c53b8ff..3f0f287b1693 100644
> --- a/drivers/staging/vt6655/desc.h
> +++ b/drivers/staging/vt6655/desc.h
> @@ -182,7 +182,7 @@ struct vnt_rdes1 {
>  
>  /* Rx descriptor*/
>  struct vnt_rx_desc {
> -	volatile struct vnt_rdes0 rd0;
> +	struct vnt_rdes0 rd0;

You can not just remove this without describing _WHY_ it is ok to do so.

Have you properly determined why it is, or is not, ok to use volatile
here?  And if so, why are you leaving:

>  	volatile struct vnt_rdes1 rd1;
>  	volatile __le32 buff_addr;
>  	volatile __le32 next_desc;

Those?

Please read up on why volatile almost never makes any sense in the
kernel (note, sometimes it does), and please write a better changelog
text for when you submit the next version of this patch series.

thanks,

greg k-h