On Mon, Mar 29, 2021 at 04:57:55PM +0200, Thomas Gleixner wrote:
> I think adjtimex is the right place and not yet another random file
> somewhere. Something like the below.
Perfect.
Acked-by: Richard Cochran <richardcoch...@gmail.com>
> ---
> include/uapi/linux/timex.h | 7 +++++--
> kernel/time/ntp.c | 4 +++-
> 2 files changed, 8 insertions(+), 3 deletions(-)
>
> --- a/include/uapi/linux/timex.h
> +++ b/include/uapi/linux/timex.h
> @@ -188,9 +188,12 @@ struct __kernel_timex {
> #define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */
> #define STA_CLK 0x8000 /* clock source (0 = A, 1 = B) (ro) */
>
> +#define STA_TAISET 0x10000 /* TAI offset was set via adjtimex (ro) */
> +
> /* read-only bits */
> -#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
> - STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
> +#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
> + STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | \
> + STA_CLK | STA_TAISET)
>
> /*
> * Clock states (time_state)
> --- a/kernel/time/ntp.c
> +++ b/kernel/time/ntp.c
> @@ -741,8 +741,10 @@ static inline void process_adjtimex_mode
> }
>
> if (txc->modes & ADJ_TAI &&
> - txc->constant >= 0 && txc->constant <= MAX_TAI_OFFSET)
> + txc->constant >= 0 && txc->constant <= MAX_TAI_OFFSET) {
> *time_tai = txc->constant;
> + time_status |= STA_TAISET;
> + }
>
> if (txc->modes & ADJ_OFFSET)
> ntp_update_offset(txc->offset);
