atmel_serial losing characters under libmodbus

[zentrale.at.work@gmail.com (Josef Holzmayr)]

christian pellegrin wrote:
> On Wed, Nov 11, 2009 at 1:44 PM, Josef Holzmayr
> <zentrale.at.work@gmail.com> wrote:
>> When using libmodbus on an atmel_serial line, it seems to lose about 1 char
>> in 50 that it's supposed to receive. This is independet of the baud rate, it
>> happens everywhere from 2400 to 19200. Full code excerpt from the lib is
>> below, but basically reading is just an select/read pair. Are there some
>> known issues with that particular tty device?
>>
> 
> Hi, the only serial port on AT91 that gives me troubles is the DBGU
> port which shares the interrupt with the timer tick. You see a lot of
> serial overruns there if you have the kernel compiled with HZ=1000 on
> that port (usually ttyS0).
> 

Thanks for the hint, but iv'e got this problem reproducable on ttyS2 and 
ttyS4. CONFIG_HZ is 128, and whats really interesting: if you use an 
usb-to-serial converter instead, everything works like a charm.

-- 
Josef"ZaP" Holzmayr

"Never underestimate the bandwidth of a freight train full of DAT tapes. 
Just latency might be an issue"