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

From: David Sterba <[email-masked]>
Date: Wed, 28 Jul 2021 23:37:30 +0200

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/[email-masked]/)
> > 
> > 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.