Subject: Re: [PATCH v5 net-next 3/3] selftests:net: Implement ptp4l sync test using netdevsim

From: Vadim Fedorenko <[email-masked]>
Date: Tue, 5 May 2026 17:38:19 +0100

On 05/05/2026 17:22, Maciek Machnikowski wrote:
> 
> 
> On 05/05/2026 14:22, Andrew Lunn wrote:
>> On Tue, May 05, 2026 at 09:36:30AM +0200, Maciek Machnikowski wrote:
>>>
>>>
>>> On 04/05/2026 19:07, Jakub Kicinski wrote:
>>>> On Sun,  3 May 2026 09:47:47 +0200 Maciek Machnikowski wrote:
>>>>> Add PTP synchronization test using ptp4l and netdevsim.
>>>>>
>>>>> The test creates two netdevsim adapters, links them together
>>>>> and runs the ptp4l leader and ptp4l follower on two ends
>>>>> of the netdevsim link and waits for the follower to report the
>>>>> synchronized state (s2) in its output log.
>>>>>
>>>>> This implementation runs the test runs over IPv4 link.
>>>>
>>>> Doesn't seem to pass on netdevsim for us:
>>>>
>>>> # 41.13 [+40.95] # ptp4l follower did not reach locked state (s2) within 40s
>>>> # 41.13 [+0.00] # Follower log (last 10 lines): ptp4l[2179.605]: ioctl SIOCETHTOOL failed: Operation not supported | ptp4l[2179.607]: interface 'eth0' does not support requested timestamping mode | failed to create a clock
>>>> # 41.15 [+0.02] # Check| At /srv/vmksft/testing/wt-2/tools/testing/selftests/net/./ptp.py, line 173, in ptp_sync_test:
>>>> # 41.15 [+0.01] # Check|     _run_ptp4l_wait_sync(nsimsv.ifname, nsimcl.ifname, nssv.name, nscl.name)
>>>> # 41.16 [+0.01] # Check| At /srv/vmksft/testing/wt-2/tools/testing/selftests/net/./ptp.py, line 99, in _run_ptp4l_wait_sync:
>>>> # 41.17 [+0.01] # Check|     ksft_true(False, "PTP sync timeout")
>>>> # 41.17 [+0.00] # Check failed False does not eval to True PTP sync timeout
>>>> # 41.32 [+0.16] not ok 1 ptp.ptp_sync_test
>>>> # 41.33 [+0.00] # Totals: pass:0 fail:1 xfail:0 xpass:0 skip:0 error:0
>>>>
>>>> Anything we need to do?
>>>
>>> Can you share the config file you used? Seems the PTP clock was not
>>> found which may lead to PTP_1588_CLOCK_MOCK not being enabled?
>>
>> Shouldn't the configuration file be part of the test?
>>
>> 	Andrew
> 
> I meant the kernel config. The PTP emulation requires PTP Mock to be
> enabled, as that's the backbone for generating timestamps. If it's
> disabled - netdevsim netdevs will report no timestamping support, as in
> the example above.
> - Maciek

tools/testing/selftests/drivers/net/netdevsim/config has
CONFIG_PTP_1588_CLOCK_MOCK=y

but maybe no CONFIG_PTP_1588_CLOCK ?