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Message-ID: <87a5v8a0zv.fsf@kurt>
Date: Thu, 03 Aug 2023 12:12:04 +0200
From: Kurt Kanzenbach <kurt@...utronix.de>
To: Johannes Zink <j.zink@...gutronix.de>, Giuseppe Cavallaro
<peppe.cavallaro@...com>, Alexandre Torgue <alexandre.torgue@...s.st.com>,
Jose Abreu <joabreu@...opsys.com>, "David S. Miller"
<davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski
<kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Maxime Coquelin
<mcoquelin.stm32@...il.com>, Richard Cochran <richardcochran@...il.com>,
Russell King <linux@...linux.org.uk>
Cc: patchwork-jzi@...gutronix.de, netdev@...r.kernel.org,
linux-stm32@...md-mailman.stormreply.com,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
kernel@...gutronix.de, kernel test robot <lkp@...el.com>
Subject: Re: [PATCH v3 0/2] net: stmmac: correct MAC propagation delay
On Wed Aug 02 2023, Johannes Zink wrote:
> Hi Kurt,
>
> On 8/2/23 12:10, Kurt Kanzenbach wrote:
>> On Tue Aug 01 2023, Johannes Zink wrote:
>>> ---
>>> Changes in v3:
>>> - work in Richard's review feedback. Thank you for reviewing my patch:
>>> - as some of the hardware may have no or invalid correction value
>>> registers: introduce feature switch which can be enabled in the glue
>>> code drivers depending on the actual hardware support
>>> - only enable the feature on the i.MX8MP for the time being, as the patch
>>> improves timing accuracy and is tested for this hardware
>>> - Link to v2: https://lore.kernel.org/r/20230719-stmmac_correct_mac_delay-v2-1-3366f38ee9a6@pengutronix.de
>>>
>>> Changes in v2:
>>> - fix builds for 32bit, this was found by the kernel build bot
>>> Reported-by: kernel test robot <lkp@...el.com>
>>> Closes: https://lore.kernel.org/oe-kbuild-all/202307200225.B8rmKQPN-lkp@intel.com/
>>> - while at it also fix an overflow by shifting a u32 constant from macro by 10bits
>>> by casting the constant to u64
>>> - Link to v1: https://lore.kernel.org/r/20230719-stmmac_correct_mac_delay-v1-1-768aa4d09334@pengutronix.de
>>>
>>> ---
>>> Johannes Zink (2):
>>> net: stmmac: correct MAC propagation delay
>>> net: stmmac: dwmac-imx: enable MAC propagation delay correction for i.MX8MP
>>
>> Tested on imx8mp <-> TSN Switch <-> x86 with i225:
>>
>> Before your patch:
>>
>> |ptp4l -i eth0 -f configs/gPTP.cfg --summary_interval=5 -m
>> |ptp4l[139.274]: rms 9 max 27 freq +29264 +/- 13 delay 347 +/- 2
>> |ptp4l[171.279]: rms 10 max 24 freq +29257 +/- 13 delay 344 +/- 2
>> |ptp4l[203.283]: rms 10 max 24 freq +29254 +/- 13 delay 347 +/- 2
>> |ptp4l[235.288]: rms 9 max 24 freq +29255 +/- 13 delay 346 +/- 1
>> |ptp4l[267.292]: rms 9 max 28 freq +29257 +/- 13 delay 347 +/- 2
>>
>> After:
>>
>> |ptp4l -i eth0 -f configs/gPTP.cfg --summary_interval=5 -m
>> |ptp4l[214.186]: rms 9 max 29 freq +28868 +/- 16 delay 326 +/- 2
>> |ptp4l[246.190]: rms 8 max 22 freq +28902 +/- 15 delay 329 +/- 2
>> |ptp4l[278.194]: rms 9 max 24 freq +28930 +/- 15 delay 325 +/- 1
>> |ptp4l[310.199]: rms 9 max 25 freq +28956 +/- 15 delay 327 +/- 3
>> |ptp4l[342.203]: rms 9 max 27 freq +28977 +/- 14 delay 327 +/- 1
>>
>> And the derived register values:
>>
>> |[ 15.864016] KURT: PTP_TS_INGR_CORR_NS: 3147483248 PTP_TS_INGR_CORR_SNS: 0
>> |[ 15.870862] KURT: PTP_TS_EGR_CORR_NS: 400 PTP_TS_EGR_CORR_SNS: 0
>> |[ 20.000962] KURT: PTP_TS_INGR_CORR_NS: 3147483636 PTP_TS_INGR_CORR_SNS: 0
>> |[ 20.007809] KURT: PTP_TS_EGR_CORR_NS: 12 PTP_TS_EGR_CORR_SNS: 0
>>
>> So, seems to work:
>>
>> Tested-by: Kurt Kanzenbach <kurt@...utronix.de> # imx8mp
>
> Thank you for testing!
> Johannes
AFAICT from the manuals the MAC propagation delay should be corrected
for the Intel TSN NIC(s) as well. I'll follow up with testing and a
patch when this set is merged.
Thanks,
Kurt
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