diff options
| author | Jacob Keller <jacob.e.keller@intel.com> | 2025-09-18 17:33:18 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-09-22 11:36:30 -0700 |
| commit | cd875625b475dc4e28ac302ccb3422cc9f678f89 (patch) | |
| tree | a28142a577e08b4cf3697bc453bf6ffb40bb72d1 | |
| parent | 3200fdd4021de1d182fa3b6db5ad936d519f3848 (diff) | |
ptp: document behavior of PTP_STRICT_FLAGS
Commit 6138e687c7b6 ("ptp: Introduce strict checking of external time stamp
options.") added the PTP_STRICT_FLAGS to the set of flags supported for the
external timestamp request ioctl.
It is only supported by PTP_EXTTS_REQUEST2, as it was introduced the
introduction of the new ioctls. Further, the kernel has always set this
flag for PTP_EXTTS_REQUEST2 regardless of whether or not the user requested
the behavior.
This effectively means that the flag is not useful for userspace. If the
user issues a PTP_EXTTS_REQUEST ioctl, the flag is ignored due to not being
supported on the old ioctl. If the user issues a PTP_EXTTS_REQUEST2 ioctl,
the flag will be set by the kernel regardless of whether the user set the
flag in their structure.
Add a comment documenting this behavior in the uAPI header file.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>
Tested-by: James Clark <jjc@jclark.com>
Link: https://patch.msgid.link/20250918-jk-fix-bcm-phy-supported-flags-v1-3-747b60407c9c@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/uapi/linux/ptp_clock.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h index 18eefa6d93d6..2c3346e91dbe 100644 --- a/include/uapi/linux/ptp_clock.h +++ b/include/uapi/linux/ptp_clock.h @@ -37,6 +37,9 @@ /* * flag fields valid for the new PTP_EXTTS_REQUEST2 ioctl. + * + * Note: PTP_STRICT_FLAGS is always enabled by the kernel for + * PTP_EXTTS_REQUEST2 regardless of whether it is set by userspace. */ #define PTP_EXTTS_VALID_FLAGS (PTP_ENABLE_FEATURE | \ PTP_RISING_EDGE | \ |