CC: UNGLinuxDriver@microchip.com CC: netdev@vger.kernel.org Hi Matt, hi Brian, although I did the initial development of the KSZ PTP patches, this never went into our final products. Because of this, I am quite happy that Arun from Microchip took over this and made several improvements. The E2E patch was originally rejected (AFAIR), because the KSZ applies (unwanted) filtering on the PTP messages. For E2E this means, that the KSZ hardware filter needs to "know" whether this node is currently master or slave clock. As there is no (and probably never will be) interface between ptp4l and the kernel for communicating the current master/slave state, there was no interest in merging this. As we do not use PTP in our current software, I have only forward ported the patch(es) for being compile clean (see attachment). But I haven't done any real tests with newer kernels / ptp4l versions. Unfortunately I will not be able to spent any time on this for the next 3 weeks. If the problem still persists then, I can try to have a look on this. If you find the solution yourself, I would be happy getting an update on this. regards, Christian On Wednesday, 29 April 2026, 21:27:12 CEST, matt.becker@L3Harris.com wrote: > Christian/Arun, > > My name is Matt Becker. I work with Brian Hutchinson at L3Harris. > > A few years back we received & applied patches (net-dsa-microchip-ptp*) from Christian for our embedded board (imx8mm Arm processor + KSZ Microchip part). At the time these patches were developed for Yocto Dunfell (3.1) + Linux Kernel 5.10.69 + linuxptp-2.0 . > > We followed up and reapplied these patches with success on the same board when we upgraded to Yocto Kirkstone (4.0.x) + Linux Kernel 6.1.38 + linuxptp-3.1.1. > > We’re now attempting to bring this same board up to the most recent Yocto LTS release (Scarthgap 5.0.16) + Linux Kernel 6.6.50 + linuxptp-4.1 . This is where we’re running into some difficulty. > > It looks like most of the patches from a few years back were already merged back to the 6.6 kernel level. I only had to re-apply the patch 0001-net-dsa-microchip-ksz9477-add-E2E-support.patch as this was not merged back. It seems this change alone might not be sufficient. Our Scarthgap board is now able to select a grandmaster clock and it is able to receive adjustments. However, the master_offset values are very large, and PTP never converges. > > My suspicion is that I may need other changes to make this work on this new OS/kernel/PTP configuration. > > I was wondering if you might be able to offer any guidance: > > * Have you ever tried bringing this functionality (net-dsa-microchip-ksz9477-add-E2E-support) forward to a newer Linux kernel and/or PTP? > * If so, do you have any unofficial patches we might be able to try? > * If not, do you have any other advice on a path forward (e.g. changes that might be necessary outside of the original patches)? > > I attached an email thread with myself & Brian that has a little bit more detail. > > If you have any ideas or help you can offer it would be greatly appreciated! > > Sincerely, > > -Matt Becker > > matt.becker@L3Harris.com > (585) 369-1184 > > > > CONFIDENTIALITY NOTICE: This email and any attachments are for the sole use of the intended recipient and may contain material that is proprietary, confidential, privileged or otherwise legally protected or restricted under applicable government laws. Any review, disclosure, distributing or other use without expressed permission of the sender is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies without reading, printing, or saving. > >