Messages in this thread Patch in this message | | | From | Paul Kocialkowski <> | Subject | [PATCH v7 1/4] media: v4l2-ctrl: Add a comment on why we zero out compound controls fields | Date | Thu, 25 Jul 2019 20:55:59 +0200 |
| |
Since it's not necessarily very explicit why we need to zero some fields in std_validate_compound, add a comment before the function to explain why, which should help as a reminder.
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> --- drivers/media/v4l2-core/v4l2-ctrls.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c index 76fa2db0e8fb..cd1ae016706f 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls.c +++ b/drivers/media/v4l2-core/v4l2-ctrls.c @@ -1645,6 +1645,10 @@ static void std_log(const struct v4l2_ctrl *ctrl) #define zero_padding(s) \ memset(&(s).padding, 0, sizeof((s).padding)) +/* + * Compound controls validation requires setting unused fields/flags to zero + * in order to properly detect unchanged controls with std_equal's memcmp. + */ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx, union v4l2_ctrl_ptr ptr) { -- 2.22.0
| |