i.MX RT10xx boards fail to initialize when Ethernet is enabled

[MaureenHelm]

Describe the bug
The kernel fails to initialize on i.MX RT10xx boards when Ethernet is enabled because the board-level PHY reset routine mimxrt1064_evk_phy_reset() never completes.

The PHY reset occurs in PRE_KERNEL_2 and invokes k_busy_wait().

The system clock driver is initialized in PRE_KERNEL_2.

Commit f0b3146 affected the relative order of these two operations, causing the PHY reset to occur before the system clock driver is initialized.

Found while experimenting with #37863

To Reproduce

$ west build -p auto -b mimxrt1064_evk samples/net/dhcpv4_client
$ west flash

No output on the console.

Expected behavior
Boot banner and assigned IP address to print on the console.

Impact
Affects all i.MX RT boards that currently support Ethernet: mimxrt1020_evk, mimxrt1050_evk, mimxrt1060_evk, mimxrt1064_evk

Logs and console output
There is no console output.

Environment (please complete the following information):

• OS: Linux
• Toolchain zephyr-sdk-0.13.0
• Commit fd864c6

Additional context
The following is a cheap fix, but there may be a more robust way to do it.

$ git diff
diff --git a/boards/arm/mimxrt1064_evk/pinmux.c b/boards/arm/mimxrt1064_evk/pinmux.c
index 484a9a9ca6..ce31f5c2d9 100644
--- a/boards/arm/mimxrt1064_evk/pinmux.c
+++ b/boards/arm/mimxrt1064_evk/pinmux.c
@@ -351,5 +351,5 @@ static int mimxrt1064_evk_phy_reset(const struct device *dev)
 
 SYS_INIT(mimxrt1064_evk_init, PRE_KERNEL_1, 0);
 #if DT_NODE_HAS_STATUS(DT_NODELABEL(enet), okay) && CONFIG_NET_L2_ETHERNET
-SYS_INIT(mimxrt1064_evk_phy_reset, PRE_KERNEL_2, 0);
+SYS_INIT(mimxrt1064_evk_phy_reset, PRE_KERNEL_2, 1);
 #endif

cc: @dleach02 @mmahadevan108 @hakehuang @dcpleung @aunsbjerg

[hakehuang]

in this weekly testing all RT serieses board fails. and this fix work for mimxrt1060_evk.

[aunsbjerg]

Do we want to wait for a robust fix or go with the quick fix for now? I can update #37863 with the quick fix if we want to get that merged sooner rather than later.

[dcpleung]

The posted fix is probably the best we can do right now. The ordering of two SYS_INIT() and device init having the same init level and priority depends on the how files are linked. So a strict ordering needs to be done manually, until we have device dependency baked in the init code.

[dleach02]

@MaureenHelm, since there is a dependency, maybe we can be a bit more explicit by doing something like the following:

/* 
 * PHY reset has a dependency on SYSTEM Clock being initialized so ensure that the 
 * reset function is called after the system clock is initialized.
 */
SYS_INIT(mimxrt1064_evk_phy_reset, PRE_KERNEL_2, CONFIG_SYSTEM_CLOCK_INIT_PRIORITY+1);

[hakehuang]

this issue is still in 2.7.0-RC1