Re: [Linuxptp-users] recvmsg tx timestamp failed: Resource temporarily unavailable

[Richard C. <ric...@gm...>]

On Sat, Feb 09, 2013 at 06:22:51PM +0530, Rayagond Kokatanur wrote:
> 
> So once SLAVE sync to MASTER then ptp stack should not call .adjfreq api
> right, unless there is change in MASTER time.

No, the slave will continuously adjust its frequency to track the
master.
 
> But how 0xF0000029 value wrt 66MHz clock ?

ifr=66666666		# input frequency
nfr=62500000		# nominal frequency
fdr=ifr/nfr		# frequency division ratio
addend=ceil(2^32/fdr)

So addend is 4026531881 or 0xF0000029.

> In our device the way driver need to update the ADDEND registers is same as
> ixp device ie (2^32)/freq_ratio, where freq_ratio = ptp_clock_freq/50000000.
> 
> So in my case ptp clock freq or system clock freq is 62.5MHz, so DEFAULT
> value i am taking is = ((2^32) * 50000000)/62500000 = 0xCCCCCC.
> 
> Is my default addend value correct ?

With ifr=62500000 and nfr=50000000, then addend is 0xCCCCCCCD, and
max_adj is 249999999.

But, then again, I don't know anything about your hardware. You will
have to confirm the correct values yourself (or publish your data
sheet).

HTH,
Richard