Le 11/5/2007, "Jan Kiszka" <[EMAIL PROTECTED]> a écrit:

>Maksym Veremeyenko wrote:
>> CHABAL David пишет:
>> 
>>> I met some trouble with the 16550A driver provided in Xenomai 2.3.1
>>> and my Moxa cards (PCI / 8 * RS232 / 168U ).
>>>
>>> It was a problem of baudrate computation before setting the LCR_DLAB
>>> register.
>>>
>>> The formula implemented by the Xenomai driver is different from the one
>>> provided by Moxa. So I copy/paste the formula from the mxser.c file
>>> (present in the
>>> kernel distro), and it seems to work fine.
>>>
>>> I think it's Moxa card dependant, may be caused by the high default baud
>>> rate of this card.
>> 
>> I have two Moxa boards with no problem, possible you need to specify 
>> 'baud_base' param.
>> 
>> I my case :
>> 
>> # 8 ports board:
>> /sbin/modprobe xeno_16550A \
>> ioaddr=0x1000,0x1008,0x1010,0x1018,0x1020,0x1028,0x1030,0x1038 \
>> irq=9,9,9,9,9,9,9,9 \
>> baud_base=921600,921600,921600,921600,921600,921600,921600,921600
>> 
>> # 2 ports board + onboards:
>> /sbin/modprobe xeno_16550A ioaddr=0x3f8,0x2f8,0xdf00,0xdf08 
>> irq=4,3,11,11 baud_base=115200,115200,921600,921600
>> 
>
>Interesting. That would leave us just with the generic fix to catch
>baud_rate==0. Far more attractive. :)
>
>David, can you confirm this? Weren't you just aware of the baud_base
>parameter?

I'm not totally convinced because if I compute by hand the DLAB register
with the 19200 value (my config):

With the moxa driver:
  baud_div = 912.600 / 19.200 = 47

With the Xeno driver:
  baud_div = (912.600 - 9600) / 19.200 = 47

Grrr, it's ok here because the rounded values are the same because the
baud base is biggest than the speed requested, but I think a problem can
occur with 115200 or more, example:

moxa: 912.600/115.200 = 8
xeno: = 7

Maksym, what is the kind of yours connections ? (PC <-> PC with the same
moxa cards inside the 2 boxes, or PC <-> other device ) ? (In the 1st
the case the both clocks are configured with the same value.)

I find the pb by seeing the signals with an oscilloscope

David

>
>Jan
>

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