The PTP core falls back to gettimex64 and getcrosststamp when getcycles64 or getcyclesx64 are not implemented. This causes the CYCLES ioctls to retrieve PHC real time instead of free-running cycles. Reject PTP_SYS_OFFSET_{PRECISE,EXTENDED}_CYCLES for clocks without free-running counter support since the result would represent PHC real time and system time rather than cycles and system time. Fixes: faf23f54d366 ("ptp: Add ioctl commands to expose raw cycle counter values") Signed-off-by: Carolina Jubran Reviewed-by: Dragos Tatulea Reviewed-by: Tariq Toukan --- drivers/ptp/ptp_chardev.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index 8106eb617c8c..c61cf9edac48 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -561,10 +561,14 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd, return ptp_mask_en_single(pccontext->private_clkdata, argptr); case PTP_SYS_OFFSET_PRECISE_CYCLES: + if (!ptp->has_cycles) + return -EOPNOTSUPP; return ptp_sys_offset_precise(ptp, argptr, ptp->info->getcrosscycles); case PTP_SYS_OFFSET_EXTENDED_CYCLES: + if (!ptp->has_cycles) + return -EOPNOTSUPP; return ptp_sys_offset_extended(ptp, argptr, ptp->info->getcyclesx64); default: -- 2.38.1