Errata doc: https://www.ti.com/lit/pdf/sprz457
Errata ID i2331 CPSW: Device lockup when reading CPSW registers
Details: A device lockup can occur during the second read of any CPSW
subsystem register after any MAIN domain power on reset (POR). A MAIN
domain POR occurs using the hardware MCU_PORz signal, or via software
using CTRLMMR_RST_CTRL.SW_MAIN_POR or CTRLMMR_MCU_RST_CTRL.SW_MAIN_POR.
After these resets, the processor and internal bus structures may get
into a state which is only recoverable with full device reset using
MCU_PORz.
Due to this errata, Ethernet boot should not be used on this device.
Workaround(s): To avoid the lockup, a warm reset should be issued after
a MAIN domain POR and before any access to the CPSW registers. The warm
reset realigns internal clocks and prevents the lockup from happening.
Workaround above errata by calling do_reset() in case of cold boot in
order to trigger warm reset. This needs enabling SYSRESET driver in R5
SPL to enable TI SCI reset driver.