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

[Nam Cao]

On Fri, Sep 9, 2022 at 8:03 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> 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@xxxxxxxxx>
> > ---
> >  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?

I did not carefully look at the volatile usage here. After looking at it
again, using volatile is actually valid: the structure resides on coherent
memory.

Sorry for being careless.

Best regards,
Nam