On Fri, 2008-08-08 at 10:58 +0200, Segher Boessenkool wrote:
> > I don't know yet for sure what happens, but a quick look at the commit
> > seems to show that the driver synchronously spin-waits for up to 2.5ms
>
> That's what the comment says, but the code says 2.5 _seconds_:
>
> + /* Wait for up to 2.5 milliseconds */
> + for (i = 0; i < 250000; i++) {
> + if (!(tr32(GRC_RX_CPU_EVENT) & GRC_RX_CPU_DRIVER_EVENT))
> + break;
> + udelay(10);
> + }
>
> (not that milliseconds wouldn't be bad already...)
Right, indeed. I think we have a good candidate for the problem :-) I'll
verify that on monday. Now, that leads to two questions:
- What such a synchronous and potentially horribly slow code is
going in a locked section or a timer interrupts ? Ie, the link
watch should probably move to a workqueue if that is to remain,
or the code turned into a state machine that periodically check for
events, or whatever is more sane than the above.
- The code should at least display some error and do something sane in
case of timeout such as disabling the new UMP feature instead of
repeatedly looping ...
- If this is indeed our problem (timing out in the code above), why is
our firmware not emitting the requested event -> maybe the PowerStations
need a tg3 firmware update.
Matt, what's your take on this ?
Cheers,
Ben.
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