Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> writes: > On Tue, Oct 15, 2024 at 12:54:13PM +0200, Sven Schnelle wrote: >> To allow users to have stable device names with the help of udev, >> add the name to the udev event that is sent when a new PtP clock >> is available. The key is called 'PTP_CLOCK_NAME'. > > Where are you documenting this new user/kernel api you are adding? > >> >> Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx> >> --- >> drivers/ptp/ptp_clock.c | 11 ++++++++++- >> 1 file changed, 10 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c >> index c56cd0f63909..15937acb79c6 100644 >> --- a/drivers/ptp/ptp_clock.c >> +++ b/drivers/ptp/ptp_clock.c >> @@ -25,9 +25,11 @@ >> #define PTP_PPS_EVENT PPS_CAPTUREASSERT >> #define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC) >> >> +static int ptp_udev_uevent(const struct device *dev, struct kobj_uevent_env *env); >> const struct class ptp_class = { >> .name = "ptp", >> - .dev_groups = ptp_groups >> + .dev_groups = ptp_groups, >> + .dev_uevent = ptp_udev_uevent >> }; >> >> /* private globals */ >> @@ -514,6 +516,13 @@ EXPORT_SYMBOL(ptp_cancel_worker_sync); >> >> /* module operations */ >> >> +static int ptp_udev_uevent(const struct device *dev, struct kobj_uevent_env *env) >> +{ >> + struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev); >> + >> + return add_uevent_var(env, "PTP_CLOCK_NAME=%s", ptp->info->name); > > Why is this needed? Can't you get the name from the sysfs paths, the > symlink should be there already. You mean the 'clock_name' attribute in sysfs? That would require to write some script to iterate over all ptp devices and check the name, or is there a way to match that in udev?