[U-Boot] Potential issue with recent OMAP PRCM struct unification

[Michael Cashwell]

Greetings,

I think <http://patchwork.ozlabs.org/patch/218063/> or something related to it has confused OMAP4 clock init. I haven't entirely unraveled the onion but wanted to ping the list to see if this is known or I'm off in the weeds.

Using u-boot master at commit a268170 in DEBUG mode the SPL says (in part):

Enable clock module - 4a008e20
Enable clock module - 4a008e28
Enable clock module - 4a008e40  << later builds omit
Enable clock module - 4a009338  << these two clocks
Enable clock module - 4a004528
Enable clock module - 4a004530
Enable clock module - 4a004538

That build works. But by commit 417c558 the 2 clocks noted are omitted and the later call to get_ram_size() hangs.

In tracing this I found that the prcm structure initializes one field (cm_l3instr_intrconn_wp1_clkct) but then enable_non_essential_clocks() passes an array populated using a different field (cm_l3instr_intrconn_wp1_clkctrl) to do_enable_clocks(). That latter uninitialized field is zero which terminates that clock init array and results in the two clock omissions above.

Searching for this and leaving out omap5 for clarity I see:

cashwell.ubuntu:u-boot$ rgrep cm_l3instr_intrconn_wp1_clkct | grep -v omap5
./arch/arm/cpu/armv7/omap4/prcm-regs.c:	.cm_l3instr_intrconn_wp1_clkct = 0x4a008e40,
./arch/arm/cpu/armv7/omap4/hw_data.c:		(*prcm)->cm_l3instr_intrconn_wp1_clkctrl,
./arch/arm/include/asm/omap_common.h:	u32 cm_l3instr_intrconn_wp1_clkctrl;
./arch/arm/include/asm/omap_common.h:	u32 cm_l3instr_intrconn_wp1_clkct;

On first blush, it looks like having both cm_l3instr_intrconn_wp1_clkct and cm_l3instr_intrconn_wp1_clkctrl is a mistake.

If that's true can anyone say which should be eliminated and whether or not the order of fields in struct prcm_regs matters?

Thanks,
-Mike Cashwell