Re: [GIT PULL] for testing: OMAP hwmod driver conversions: watchdog, UART, i2c

[Kevin Hilman <khilman@deeprootsystems.com>]

"Nayak, Rajendra" <rnayak@ti.com> writes:

[...]

>> >>
>> >> Hmm, this fault is very early and long before any PM code has
>> >> initialzed.  I suspect this happens with the master branch too ??
>> >
>> > I've reproduced this now, and it doesn't happen on the master branch and
>> > only happens after merge pm-hwmods.
>> >
>> > Debugging now...
>> 
>> OK, so this failure is (somehow) related to the i2c hwmods, but I did
>> not figure out how.  Rajendra, can you dig into this?  It only seems to
>> happen on 2420/n800, and all other platforms seem OK.
>
> Hi Kevin,
>
> I was able to reproduce the crash on the n800 and have been debugging
> it for a while.  Like you said putting a HWMOD_INIT_NO_RESET did not
> seem to fix it for me, and the only way I can get the n800 to
> completely bootup is by removing the sysc completely for i2c.  That is
> quite surprising since the only thing that can be done using the
> sysconfig on omap2420 is a softreset.
>
> I verified that its not the sysc read itself that causes a crash
> (clocks seem to be enabled, idlest seems fine) but somehow just these
> sysc reads (if I have HWMOD_INIT_NO_RESET set) seem to be enough to
> cause the crash.  Nothing gets written back to the sysc register
> either.  I was suspecting the omap_readl's done in hmwod framework on
> the 16bit 2420 registers to be an issue, but I am yet to figure out
> how.
>
> I am debugging this further, but in the meantime since this is gating
> all other patches to get merged in omap-testing, should I just remove
> the sysc for i2c on 2420? The only thing it will prevent is a i2c
> softreset at boot, which anyway does not seem to be causing any issues
> on n800.

For omap-testing, I will just drop the i2c series for now until this is
better understood.

Happy debugging!   this sounds like a tricky one,

Kevin