Re: UART misbehaves under Linkstation/KuroBoxHG

[Oncaphillis <oncaphillis@snafu.de>]

Guennadi Liakhovetski wrote:
> On Wed, 8 Aug 2007, Oncaphillis wrote:
> 
>>  So that's ok ? No misconfiguration ? And that setserial tells
>>  me the port is 0x000 ?
> 
> Yes, everything looks ok, don't know why, setserial reports 0 here too, 
> but it doesn't cause me any (visible) problems.
> 
>>  I thought the dts file which
>>  comes with the linkstation kernel describes the ports and IRQs
>>  but poking there didn't change anything. It seems like the kernel
>>  is ignoring the serial settings in the dts-file (which I do not
>>  realy understand) all together.
> 
> Believe me, it doesn't ignore them:-) Don't know what exactly you were 
> poking at there, but it should be quite easy to break it by changing 
> clocks / address / irq...
> 
>>   I started with a debian distro
>>   http://www.kurobox.com/mwiki/index.php/Debian_sylver
>>
>>   Hmm I tried my very best to eliminate this everywhere. Actually I
>>   resurrected the ARV00 device by creating a soft link to a ttySx
>>   with during bootup within the udev filesystem.
>>
>>   <snip>
>>         if [ ! -e /dev/AVR00 ];then
>>          cat /proc/tty/driver/serial | grep 80004500 | grep -q 0:
>>            && AVR=/dev/ttyS0 || AVR=/dev/ttyS1
>>          echo "Making AVR00 link to "$AVR;
>>          ln -s $AVR /dev/AVR00
>>         fi;
>>   </snip>
>>
>> Stole the trick from the avr_evtd startup script...
> 
> Well, just do "ls -l /dev/AVR00", then "lsof /dev/ttyS0".
> 

   Oh.... that's something I should have thought about (shaking my
   head)

   I hope I found the the misconfigured part. I didn't look
   at /etc/inittab. It opens a getty on /dev/ttyS0. That
   might do the trick. Have to recompile my kernel right now with
   standard config to check this out.

> In principle, as mentioned elsewhere before, you don't need any daemons on 
> linkstation/kurobox now for "basic" operation, i.e., the kernel disables 
> the watchdog on startup, and properly sends reboot and power-off commands 
> to the AVR itself without any userspace support. So, at least for a test, 
> you could stop all those daemons. You need them though if you want to use 
> the buttons to power down / reboot / whatever, do other fancy things with 
> the AVR...

   Well ... it doesn't seem to need the daemons but at least
   the kuro_boot  script or something similar has to be executed
   once sending the right init strings to the AVR or your system
   reboots after a few minutes at least on my box.

> Another possible reason why, for example, your stty misbehaves, maybe it 
> is somehow broken in that distro? I am just using etch and things work 
> pretty well.
> 
> Thanks
> Guennadi
> ---
> Guennadi Liakhovetski