Messages in this thread | | | Subject | Re: [PATCH 1/2] PTP: introduce new versions of IOCTLs | From | Joe Perches <> | Date | Sat, 17 Aug 2019 09:17:20 -0700 |
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On Sat, 2019-08-17 at 08:59 -0700, Richard Cochran wrote: > On Wed, Aug 14, 2019 at 10:47:11AM +0300, Felipe Balbi wrote: > > The current version of the IOCTL have a small problem which prevents us > > from extending the API by making use of reserved fields. In these new > > IOCTLs, we are now making sure that flags and rsv fields are zero which > > will allow us to extend the API in the future. > > > > Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> > > --- > > drivers/ptp/ptp_chardev.c | 58 ++++++++++++++++++++++++++++++++-- > > include/uapi/linux/ptp_clock.h | 12 +++++++ > > 2 files changed, 68 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c [] > > @@ -123,9 +123,11 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) > > struct timespec64 ts; > > int enable, err = 0; > > > > + memset(&req, 0, sizeof(req)); > > Nit: please leave a blank line between memset() and switch/case.
or just initialize the declaration of req with = {}
Is there a case where this initialization is unnecessary such that it impacts performance given the use in ptp_ioctl?
caps for instance is memset to zero only in PTP_CLOCK_GETCAP
req is used in only 3 of the case blocks.
case PTP_EXTTS_REQUEST: case PTP_PEROUT_REQUEST: case PTP_ENABLE_PPS:
Maybe it would be better to move the memset(&req...) into each of the case blocks.
> > switch (cmd) { > > > > case PTP_CLOCK_GETCAPS: > > + case PTP_CLOCK_GETCAPS2: > > memset(&caps, 0, sizeof(caps)); > > caps.max_adj = ptp->info->max_adj; > > caps.n_alarm = ptp->info->n_alarm; > > Reviewed-by: Richard Cochran <richardcochran@gmail.com> >
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