Re: Preempt-RT on OMAP3?

Hugo Vincent
2009-04-07T02:44:27Z

On Tue, Apr 7, 2009 at 2:27 PM, David Brownell <david-b@pacbell.net> wrote:
>
>> > RX DMA is troublesome with the MUSB code, and there are some bugfixes
>> > pending which should affect it.  (Posted to linux-usb over the last
>> > week or two.)
>> >
>> > Do these problems show up with DMA disabled?
>>
>> I guess you mean with CONFIG_MUSB_PIO_ONLY - yes, I've tried that. I
>> don't observe the Rx DMA problems as described previously in that
>> configuration, no ........
>
> Good...

So based on what you've seen, do you think the queued patches for MUSB
you mentioned will fix these problems?

>> However I instead I see hard-lockups with
>> no obvious cause and no messages printed to the console. (The only
>> repeatable one I've found so far is exiting cyclictest with ^C. Not
>> good). These lockups could well be and probably are unrelated, but
>> none-the-less, it's very troubling!
>
> Given the bootlog excerpt you posted, I'm thinking there are
> still some basic goofy things with the RT patches you're using
> even outside the scope of MUSB.  Basic as in timer tick and
> kernel thread setup; lots of things look goofy.
>

Here is a complete boot log + config:
http://hugovincent.com/files/lkml-20090407/boot2.log

Who is working on OMAP3 -rt? Does anyone have any tips for tracking
down the apparent basic problems David mentioned (timer tick, kernel
thread setup)?

Thanks,
Hugo