DO NOT MERGE, patch 2 and 3 are duplications at differing levels (platform vs driver wide). They work fine together but it makes no sense to take both. Disclosure: I don't know much about PTP beyond what you can google in an afternoon, don't have access to documentation about the stmmac IP, and have only tested that (based on code comments and git commit history) the programming of the subsecond register (and the clock rate) makes more sense with these changes. I'm hoping to start some discussion and get some insight about this. Recently I found myself discussing PTP and some possible changes from downstream that might need to be upstreamed. In doing so, I noticed that the PTP reference clock (clk_ptp_ref) was running at a much lower value than was being discussed. Digging in a bit, nobody is calling clk_set_rate() of any value on clk_ptp_ref, so you get whatever the default rate is when enabled. On Qualcomm platforms I have access to this results in a 19.2 MHz clock instead of a possible 230.4 MHz clock. This series proposes setting the clock rate. Patch 2 is the "safe" approach where a platform must handle it, patch 3 is the big hammer where we max out the clock for all users. I think patch 2 is using a proper callback (I want to document those a bit in the future to make it easier for future folks using them). My guess is that doing this driver wide might be undesirable for some reasons I'm not aware of (right now I blindly request the max frequency but the IP could have an upper limit here, platform maintainers maybe upset if their careful validation at prior frequencies changes, etc). I've only tested that the Qualcomm boards I have access to in a remote lab still work (i.e. throughput testing, etc) and that the PTP programming is now what I expected it to be theoretically. I'd really appreciate someone with the ability (and know how!) to test PTP tried this on at least the Qualcomm platforms. Bonus points if someone explains how one would even test PTP networks like this. Thanks, Andrew Andrew Halaney (3): net: stmmac: Make ptp_clk_freq_config variable type explicit net: stmmac: dwmac-qcom-ethqos: Use max frequency for clk_ptp_ref net: stmmac: Use the max frequency possible for clk_ptp_ref .../net/ethernet/stmicro/stmmac/dwmac-intel.c | 3 +-- .../stmicro/stmmac/dwmac-qcom-ethqos.c | 18 ++++++++++++++++++ .../ethernet/stmicro/stmmac/stmmac_platform.c | 5 +++++ include/linux/stmmac.h | 4 +++- 4 files changed, 27 insertions(+), 3 deletions(-) -- 2.41.0
