[PATCH net-next v5 3/3] net: stmmac: Add DWMAC glue layer for Renesas GBETH

[Biju Das]

Hi Andrew,

> -----Original Message-----
> From: Andrew Lunn <andrew at lunn.ch>
> Sent: 21 April 2025 15:02
> Subject: Re: [PATCH net-next v5 3/3] net: stmmac: Add DWMAC glue layer for Renesas GBETH
> 
> > > On the RZ/G3E, the upstream support for testing S2R is not yet in a
> > > usable state. So for now, I'll switch to using init/exit callbacks and drop the PM callback.
> >
> > FYI, On RZ/G3E, for STR to work with mainline, we need to reinitialize the PHY.
> > I have done below changes on top of [1] to make STR working.
> 
> Can you explain why you need to reinitialise the PHY? The MAC driver should not need to do this, so
> something is wrong somewhere. If we understand the 'Why?' we can probably tell you a better way to do
> this.

You are right, reinitialization of PHY is not required.

I can confirm STR works only by adding just [1] + Restoring the direction (MII/RGMII) of IO block for
ET0/1_TXC_TXCLK (IO attribute) in the pinctrl driver.

[1]:
+		.pm		= &stmmac_pltfr_pm_ops,


Logs:
  34.081297] PM: suspend entry (deep)
[   34.086010] Filesystems sync: 0.000 seconds
[   34.094746] Freezing user space processes
[   34.101104] Freezing user space processes completed (elapsed 0.002 seconds)
[   34.108164] OOM killer disabled.
[   34.111468] Freezing remaining freezable tasks
[   34.117478] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[   34.124888] printk: Suspending console(s) (use no_console_suspend to debug)
NOTICE:  BL2: v2.10.5(release):9aa8ec5-dirty
NOTICE:  BL2: Built : 14:47:04, Feb  7 2025
NOTICE:  BL2: SYS_LSI_MODE: 0x13e06
NOTICE:  BL2: SYS_LSI_DEVID: 0x8679447
NOTICE:  BL2: SYS_LSI_PRR: 0x0
NOTICE:  BL2: Booting BL31
[   34.202183] renesas-gbeth 15c30000.ethernet eth0: Link is Down
[   34.328938] Disabling non-boot CPUs ...
[   34.338285] psci: CPU3 killed (polled 4 ms)
[   34.352108] psci: CPU2 killed (polled 0 ms)
[   34.368492] psci: CPU1 killed (polled 0 ms)
[   34.378137] Enabling non-boot CPUs ...
[   34.378137] Detected VIPT I-cache on CPU1
[   34.378137] GICv3: CPU1: found redistributor 100 region 0:0x0000000014960000
[   34.378137] CPU1: Booted secondary processor 0x0000000100 [0x412fd050]
[   34.378137] CPU1 is up
[   34.378137] Detected VIPT I-cache on CPU2
[   34.378137] GICv3: CPU2: found redistributor 200 region 0:0x0000000014980000
[   34.378137] CPU2: Booted secondary processor 0x0000000200 [0x412fd050]
[   34.378137] CPU2 is up
[   34.378137] Detected VIPT I-cache on CPU3
[   34.378137] GICv3: CPU3: found redistributor 300 region 0:0x00000000149a0000
[   34.378137] CPU3: Booted secondary processor 0x0000000300 [0x412fd050]
[   34.378137] CPU3 is up
[   34.378137] dwmac4: Master AXI performs fixed burst length
[   34.378137] renesas-gbeth 15c30000.ethernet eth0: No Safety Features support found
[   34.378137] renesas-gbeth 15c30000.ethernet eth0: IEEE 1588-2008 Advanced Timestamp supported
[   34.378137] renesas-gbeth 15c30000.ethernet eth0: configuring for phy/rgmii-id link mode
[   34.378137] OOM killer enabled.
[   34.378137] Restarting tasks ... done.
[   34.378137] random: crng reseeded on system resumption
[   34.378137] PM: suspend exit

root at smarc-rzg3e:~# ping[   34.378137] renesas-gbeth 15c30000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
 [   34.378137] mmc2: Skipping voltage switch

root at smarc-rzg3e:~# ping 192.168.10.1
PING 192.168.10.1 (192.168.10.1) 56(84) bytes of data.
64 bytes from 192.168.10.1: icmp_seq=1 ttl=64 time=0.751 ms
64 bytes from 192.168.10.1: icmp_seq=2 ttl=64 time=0.858 ms
^C
--- 192.168.10.1 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss,

Cheers,
Biju