Linux PTP mainline development war story and new features
5 hours ago
- #kernel development
- #Linux kernel
- #PTP
- A customer requested PTP support for a Marvell PHY driver, initially seeming straightforward due to existing patches.
- Two main issues were discovered: a mismatch in PTP capabilities reporting between MAC and PHY, and a risk of timestamping regression on the MACCHIATObin board.
- The solution involved upstreaming a mechanism for selecting between MAC and PHY timestamping sources, replacing old IOCTLs with a modern netlink interface.
- A long review process with 21 revisions led to the feature's inclusion in Linux mainline, benefiting many drivers.
- Although Marvell PHY PTP support remains stalled, the work improved the kernel's PTP stack and highlighted the complexities of upstream contributions.