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: faf23f54d3 ("ptp: Add ioctl commands to expose raw cycle counter values")
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20251029083813.2276997-1-cjubran@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
5a89b27afd