On 09/01/2014 07:47 PM, Sebastian Andrzej Siewior wrote:
> Comparing it with serial-omap I see the same thing: I takes approx the
> same amount of data until the first one is displayed. After a lot of
> "long" writes which wake the chip up from idle I manage to freeze both,
> the serial-omap driver and mine driver.
So after some testing:
- it happens with omap-serial as well. Especially after disabling the
LED trigger for both LEDs.
- it seemed that disabling the MDR1 check whether or not we lost
context made the problem appear less often but it was a trick. Even
with restoring the context each time I see the same problem.
- it seems to be easier to trigger with the LED trigger switched off.
However sometimes it works for 10 minutes, sometimes it triggers
after one.
- I see to face two kind of "deaths":
- the LED still goes on and off and the uart just does not respond
even if I tell the button print something on the screen (the button
also changes the frequency of the LED so I know that the button is
doing something).
Also from dumping the content of /proc/interrupts it seems that a
wake up is made, the uart should have restored the registers.
- one where the system is dead and the LED does not blink anymore.
Also my button is dead.
- disabling DMA makes the problem not go away.
- mdelay(25) in omap8250_lost_context() is long enough to drop the 403
bytes I send in my testcase. That means I see only "good" characters.
With this the box remained alive for 2h. However the uart died anyway.
>>
>> Regards,
>>
>> Tony
>>
>
Sebastian
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