Hi Richard, > On Thu, Apr 06, 2017 at 09:30:27PM +0200, Richard Cochran wrote: > Sorry, I didn't mean that those are the correct values. Those two > properties define the clock constants: > > nanoseconds = ticks * cpts_clock_mult / 2^cpts_clock_shift > > The values from the beaglebone are > > cpts_clock_mult = <0x80000000>; > cpts_clock_shift = <29>; > > and so > > nanoseconds = ticks * 2^31 / 2^29 > nanoseconds = ticks * 4 > > which is correct if the input clock is 250 MHz. If your SoC uses a > different clock, then the values in the DTS are wrong.
Than you very much for the detailed explanation. Very helpful! I dived into device tree files and couldn't yet find out how the manufacturer configures CPTS_RFT_CLK. I have the impression that it's not running at all. So I contacted them and asked if they can point me in the right direction. I'll report back as soon as I have further information. > > Is there anything else I can check? > > The two values are calculated automatically as of commit: > > v4.10-rc1~202^2~61^2~1 88f0f0b net: ethernet: ti: cpts: calc mult and shift > from refclk freq > > You can try kernel v4.10 and remove those two properties from the DTS. > It should "just work" then. That's very good news. I cloned Tis v4.10.8, but currently struggle with the manufacturers way of configuring (which is only supported by the manufacturer for the v4.1.6). I'm also going to report back if I managed to get v4.10.8 running. Tnak you very much for your support! Axel ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linuxptp-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linuxptp-users
