RE: [gentoo-embedded] High Speed Serial Problem

[Peter Bell]

G'day,

I'm porting a DOS application to Linux and have encountered problems
with the high speed serial devices from which the app receives data.

Any suggestions of what to do or where to look to solve the problems?


OK, this sounds like a timing problem to me - I assume you are controlling
the bus transceiver from your userland code?  The Linux serial handler has a
lot of buffering in it and it enables the FIFOs on the UART chip, so you may
only get an interrupt some time after the data has been received.

My first approach would be to get a scope and look at the signal lines (TX,
RX and transmit enable) and see if the timing looks plausible.  If you have
a spare I/O line you can play with, then set that up so that it pulses or
toggles when you detect a break - you can then see how long it's taking for
the code to recognize the condition.

Pete