[U-Boot] USB works (or not) depending on SYS_BOOT (with TPS65920)

[Orjan Friberg <of@flatfrog.com>]

On 2011-07-07 14:27, Orjan Friberg wrote:
> On 2011-07-07 11:37, Orjan Friberg wrote:
>> It seems the boot rom must be doing some initialization of the USB phy
>> (this is with a TPS65920).
>
> I forgot to add that I'm using a configuration header and not x-loader
> as the 1st stage bootloader.
>
> On a BeagleBoard xM (with x-loader), usb reset works fine coming out of
> a cold reset.
>
> I'd better check my configuration header.

Ok, so I've booted a u-boot with a configuration header on the xM board 
and 'usb reset' works fine after a cold boot.  Vice versa, using 
x-loader + u-boot on our own board, 'usb reset' does not work.

I'm looking at the silicon erratas for the 3730 and the TPS chip and 
found a couple of entries relating to the OTG functionality.  However, 
they don't correlate with silicon revision differences between the xM 
board and our own board (and they don't seem to apply here).

What other stuff should I be looking into?  (The xM board uses a 65950 
whereas we are using the 65920, but the errata is for all 659x0 devices.)

The 3730 TRM talks about the boot ROM doing USB PHY initialization, but 
it doesn't list any details.

Thanks for any suggestions,

Orjan

-- 
Orjan Friberg
FlatFrog Laboratories AB