Re: Nokia N900: musb is in wrong state after boot

From: joerg Reisenweber
Date: Wed Jun 08 2016 - 07:01:47 EST


On Wed 08 June 2016 13:02:00 Felipe Balbi wrote:
> Hi,
>
> Tony Lindgren <tony@xxxxxxxxxxx> writes:
> > Yeah I don't know, AFAIK we don't have a generic way to
> > force MUSB to change mode without ID pin. If you have figured
> #define MUSB_TEST_FORCE_HOST 0x80
>
> Can someone confirm on MUSB's docs (and actual running system) that this
> does what's supposed to do?



(disclaimer: all IIRC) Alas it doesn't, at least for the MentorGraphics MUSB
in OMAP3.
We use MUSB_TEST_FORCE_HOST in the H-E-N N900 hostmode hack
(http://talk.maemo.org/showthread.php?p=696115) and it's really just a test
thing that doesn't support full hostmode as we know it.

There is definitely no other way to force the state machine in MUSB core into
hostmode, than the "ID pin grounded" message from PHY via ULPI bus up to the
MUSB, whether it's real or *sw-triggered by a command to PHY*.
Shame on the MUSB core design for this.


/jOERG

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