Re: UART misbehaves under Linkstation/KuroBoxHG

Oncaphillis
2007-08-08T22:04:51Z

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