Hi,When using the R-Car H3 Starter Kit, there are variations in the time from system startup to Ethernet link-up.
What causes the Ethernet link-up time to vary?Also, can you tell me what to do to eliminate the variation in Ethernet link-up time?
[Details]We have confirmed how often the Ethernet link-up time varies.After booting a total of 10 times, the Ethernet link-up time after system booting is as follows.・ 2.5-3 sec: 6 times・ 5.5-6 sec: 4 times
After checking the details, there is no change in the driver initialization processing time, and the link-up notification from the Ethernet phy is uneven.
・ Reference (variation check)Driver initialization completion time: 48msecEthernet link-up time: 5643 msec
Driver initialization completion time: 48msecEthernet link-up time: 5643 msec
Driver initialization completion time: 48msecEthernet link-up time: 3047 msec
Driver initialization completion time: 48msecEthernet link-up time: 2442 msec
In addition, I tried setting Auto MDI / MDI-X to "OFF", setting Auto Negotiation to "OFF", and fixing it to 100Base Full, but I could not suppress the variation in Ethernet link-up time.
Thanks & Regards,
I have implemented another company's environment.I posted it because I thought there might be a point that can be considered as a general story of Ethernet.
Please close this question.
Is it impossible to keep the Ethernet link-up time constant to some extent?
Using DHCP typically results in very long init times for an Ethernet interface. Using a static IP addr removes that variable.
Hard to say what could be the reason there.By looking at the Ethernet link up you gave, I'm guessing that at 2 or 5 seconds your board is
already running Linux.
So which version of the Renesas BSP are you using ? With which Linux version and userspace ?
Please close this question.Thank you very much.
When running on Renesas Linux BSP v3.21.0, there was no variation in link-up time.
Can physical factors change the time the PHY links up? If possible, I would appreciate it if you could comment if there is a way to solve it.
Hi, Coud be great to have a reproduction protocol.Many thing can influence the startup time.Can you say US what version of the Renesas BSP you are using.
And Which rootfs image, for example Yocto dunfell core-image-minimal. And what is your way for measuring the ethernet lin-up time.Thanks,Regards
I confirmed the operation with BSP v5.1.0. elinux.org/.../v5.1.0
The measurement is obtained from the time stamp of the startup log, and is the time of "b-a".
a."igb: Intel (R) Gigabit Ethernet Network Driver" log appearsb. "Link is Up" log appears
A deviation of about 3 seconds may occur at a rate of 2-3 times out of 10 times.Is Ethernet "that kind of thing"?
Thank you so much to do these operation on BSP v5.1.0.Just a question since R-Car H3 Starter kit doesn't have an Intel Gigabit adapter,can you confirm that the behaviour that you are observing is also true by comparing
these two logs ?
[ 3.946419] Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached PHY driver (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=185)[ 6.828844] ravb e6800000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off
I tried to dive into the ethernet driver, it result that most of this delay is spent while startingautonegociation on PHY_UP event.https://github.com/renesas-rcar/linux-bsp/blob/v5.10/rcar-5.0.0.rc4/drivers/net/phy/phy.c#L1174We then start auto negociation on the micrel phy component and wait for an interrupt which will turn the ethernet adapter to running state.Regards,