Re: [PATCH 2/3] ptp: Add clock name to uevent

Greg Kroah-Hartman [off-list ref] writes:

On Tue, Oct 15, 2024 at 02:02:17PM +0200, Sven Schnelle wrote:

quoted

Greg Kroah-Hartman [off-list ref] writes:

quoted

On Tue, Oct 15, 2024 at 12:54:13PM +0200, Sven Schnelle wrote:

quoted

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?

quoted

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
---
 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?

Great, yes, it's right there.

quoted

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?

Yes there is.  Please use that :)

Indeed. Sorry, will drop the patch.