Re: [PATCH 01/64] media: omap3isp: Extract struct group for memcpy() region

David Sterba
2021-07-28T21:40:20Z

On Wed, Jul 28, 2021 at 02:37:20PM -0700, Bart Van Assche wrote:
> On 7/28/21 2:14 AM, Dan Carpenter wrote:
> > On Wed, Jul 28, 2021 at 10:59:22AM +0200, David Sterba wrote:
> >>> drivers/media/platform/omap3isp/ispstat.c | 5 +--
> >>> include/uapi/linux/omap3isp.h | 44 +++++++++++++++++------
> >>> 2 files changed, 36 insertions(+), 13 deletions(-)
> >>>
> >>> diff --git a/drivers/media/platform/omap3isp/ispstat.c b/drivers/media/platform/omap3isp/ispstat.c
> >>> index 5b9b57f4d9bf..ea8222fed38e 100644
> >>> --- a/drivers/media/platform/omap3isp/ispstat.c
> >>> +++ b/drivers/media/platform/omap3isp/ispstat.c
> >>> @@ -512,7 +512,7 @@ int omap3isp_stat_request_statistics(struct ispstat *stat,
> >>> int omap3isp_stat_request_statistics_time32(struct ispstat *stat,
> >>> struct omap3isp_stat_data_time32 *data)
> >>> {
> >>> - struct omap3isp_stat_data data64;
> >>> + struct omap3isp_stat_data data64 = { };
> >>
> >> Should this be { 0 } ?
> >>
> >> We've seen patches trying to switch from { 0 } to { } but the answer
> >> was that { 0 } is supposed to be used,
> >> http://www.ex-parrot.com/~chris/random/initialise.html
> >>
> >> (from https://lore.kernel.org/lkml/fbddb15a-6e46-3f21-23ba-b18f66e3448a@suse.com/)
> >
> > In the kernel we don't care about portability so much. Use the = { }
> > GCC extension. If the first member of the struct is a pointer then
> > Sparse will complain about = { 0 }.
>
> +1 for { }.

Oh, I thought the tendency is is to use { 0 } because that can also
intialize the compound members, by a "scalar 0" as it appears in the
code.