[Linuxptp-users] 答复: PTP

[Gao Meitao（高. <mei...@as...>]

Hi Richard:
	
 We use Arasan GEMAC-1588-AVB， clock control looks like simple,  a fix 100M clock as input,  you could change Increment Attributes Register for ethernet system timer
 I think it doen't have fine freq adjustment. So this should be reason?
 
    Register settting example 
    •  If the Increment Value is 10 and the Increment Period is 1, a value of 10 is added to 
		the counter every clock. This gives a counter operating at nanosecond resolution and 
		counts time in terms of nanoseconds. 
	•  If the Increment Value is 100 and the Increment Period is 1, a value of 100 is added 
		to the counter every clock. This gives a counter operating at 0.1 ns resolution and 
		counts time in terms of 0.1 ns.
 
Timestamping generate by hardware, be save by register,  driver read tx/rx timestamp then pass them to application.

Does ptp4l has a feather that only adjust time offset not freq ?



Thans for your reply . 





-----邮件原件-----
发件人: Richard Cochran [mailto:ric...@gm...] 
发送时间: 2022年7月6日 22:01
收件人: Gao Meitao（高玫涛） <mei...@as...>
抄送: lin...@li...
主题: Re: [Linuxptp-users] PTP

On Wed, Jul 06, 2022 at 06:07:40AM +0000, Gao Meitao（高玫涛） wrote:
> Hi all:
> 
>        I try to test ptp as slave for my evb borad, and found that it seem not work properly , as you can see from below logs
>     First run,  it seem be out of control by ptp,  after run again, thing seem work fine.
> 
> Any suggestion about this ?  thanks in advance

What device is that?

Check the implementation of the hardware and of the device driver WRT:

1. clock control

2. time stamp generation + reporting


Good luck,
Richard