Hi Ramon,
-----Original Message----- From: Ramon Fried rfried.dev@gmail.com Sent: 2021年11月17日 12:20 To: Joakim Zhang qiangqing.zhang@nxp.com Cc: Joe Hershberger joe.hershberger@ni.com; U-Boot Mailing List u-boot@lists.denx.de; Ye Li ye.li@nxp.com; Patrick Delaunay patrick.delaunay@foss.st.com; Daniil Stas daniil.stas@posteo.net; Stephen Warren swarren@nvidia.com Subject: Re: [PATCH] net: eqos: connect and config PHY from probe stage instead of starting EQOS
On Tue, Nov 16, 2021 at 1:02 PM Joakim Zhang qiangqing.zhang@nxp.com wrote:
-----Original Message----- From: Ramon Fried rfried.dev@gmail.com Sent: 2021年11月16日 18:45 To: Joakim Zhang qiangqing.zhang@nxp.com Cc: Joe Hershberger joe.hershberger@ni.com; U-Boot Mailing List u-boot@lists.denx.de; Ye Li ye.li@nxp.com; Patrick Delaunay patrick.delaunay@foss.st.com; Daniil Stas daniil.stas@posteo.net; Stephen Warren swarren@nvidia.com Subject: Re: [PATCH] net: eqos: connect and config PHY from probe stage instead of starting EQOS
On Tue, Nov 16, 2021 at 10:04 AM Joakim Zhang qiangqing.zhang@nxp.com wrote:
Hi Ramon,
-----Original Message----- From: Ramon Fried rfried.dev@gmail.com Sent: 2021年11月16日 13:57 To: Joakim Zhang qiangqing.zhang@nxp.com Cc: Joe Hershberger joe.hershberger@ni.com; U-Boot Mailing List u-boot@lists.denx.de; Ye Li ye.li@nxp.com; Patrick Delaunay patrick.delaunay@foss.st.com; Daniil Stas daniil.stas@posteo.net; Stephen Warren swarren@nvidia.com Subject: Re: [PATCH] net: eqos: connect and config PHY from probe stage instead of starting EQOS
On Wed, Nov 10, 2021 at 7:42 AM Joakim Zhang qiangqing.zhang@nxp.com wrote:
For EQOS ethernet, it will do phy_connect() and phy_config() when start the ethernet (eqos_srart()), users need wait seconds for PHY auto negotiation to complete when do tftp boot. phy_config() -> board_phy_config() -> phydev->drv->config() // i.MX8MP/DXL use
realtek PHY
-> rtl8211f_config() -> genphy_config_aneg() ->genphy_restart_aneg()
// restart auto-nego, then need seconds to complete
To avoid wasting time, we can move PHY connection and configuration from eqos_start() to eqos_probe(). This patch also moves clock setting from eqos_start() to eqos_probe() as MDIO access need CSR clock, there is no function change.
Tested-on: i.MX8MP & i.MX8DXL
Before: u-boot=> run netboot Booting from net ... ethernet@30bf0000 Waiting for PHY auto negotiation to
complete.......
done BOOTP broadcast 1 DHCP client bound to address 10.193.102.192 (313 ms) Using ethernet@30bf0000 device TFTP from server 10.193.108.176; our IP address is 10.193.102.192; sending through gateway 10.193.102.254 After: u-boot=> run netboot Booting from net ... BOOTP broadcast 1 DHCP client bound to address 10.193.102.192 (454 ms) Using ethernet@30bf0000 device TFTP from server 10.193.108.176; our IP address is 10.193.102.192; sending through gateway 10.193.102.254
How much time do you save exactly, Is it the ~140ms you show here at the commit log ?
Exactly not. This time points to DHCP client bound to address, not the time
this patch saves.
How can we evaluate the time we save? Please see the log:
Before: Booting from net ... ethernet@30bf0000 Waiting for PHY auto negotiation to
complete.......
done
BOOTP broadcast 1After: Booting from net ... BOOTP broadcast 1
And you need to check the related code: drivers/net/dwc_eth_qos.c: phy_startup ->...-> drivers/net/phy/phy.c: genphy_update_link()
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fso
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while (!(mii_reg & BMSR_ANEGCOMPLETE)) { /* * Timeout reached ? */ if (i > (PHY_ANEG_TIMEOUT / 50)) { printf(" TIMEOUT !\n"); phydev->link = 0; return -ETIMEDOUT; } if (ctrlc()) { puts("user interrupt!\n"); phydev->link = 0; return -EINTR; } if ((i++ % 10) == 0) printf("."); mii_reg = phy_read(phydev,MDIO_DEVAD_NONE, MII_BMSR);
mdelay(50); /* 50 ms */ }We can see that one "." is about 500ms, so from the log, we save about
500*7=3500ms=3.5s, this also means that PHY needs about 3.5s to complete auto-nego.
I also described this in the commit message, "users need wait seconds for
PHY auto negotiation to complete when do tftp boot", may not quite clear, I will improve it.
Best Regards, Joakim Zhang
NACK. Hi Joakim. It's currently working like that for all network drivers, it's not specific What you're currently suggesting is that the link will be brought up automatically for all users, even if they're not interested in
network booting.
That won't work.
Hi Ramon,
I am not quite understand you mean, I only connect and config the PHY in the MAC probe stage, yes, the link should be brought up, but startup
PHY still in MAC open operation, just attaching PHY to MAC in MAC probe, seems not a problem. Is there any side effect? The link up is a side effect, the U-Boot device model works in lazy loading mode, where stuff is initialized only when needed. This works the same for all phys in all places.
Understand, thanks.
Additionally, I'm not following how much time can you actually save, how much time passes between the probe() function and start() function in your setup ? how could it be seconds ?
Actually, Realtek PHY(RTL8211FDI) at my side, it needs about 3.5s to complete auto-negotiation. If we connect and config PHY in probe(), it _may_ complete auto-nego when user start network (start()), as you said, yes, if we start network quickly, we also need some time to wait it to complete. However, at least, we can save some time compared to connect and config PHY in start(), where we need wait about 3.5s to complete auto-nego.
We did the same thing in FEC driver:
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsour
ce.denx.de%2Fu-boot%2Fu-boot%2F-%2Fblob%2Fmaster%2Fdrivers%2Fnet %2Ffec
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True, that's an example that contradicts what I just said, but it's wrong.
OK.
Best Regards, Joakim Zhang
Best Regards, Joakim Zhang
Thanks, Ramon