uart vs sio differences ?
Mike Tancsa
mike at sentex.net
Tue Dec 9 14:57:24 UTC 2008
At 05:39 PM 12/8/2008, Mike Tancsa wrote:
>What it appears to be is that as long as data is coming in, even at
>1200bps, the ioctl FIONREAD returns zero and an actual read does not
>return any data until there is either a pause in the data coming in
>or possibly when we do a xmit/write at which point the accumulated
>data is available for us to read.
>
>We dont know if this is due to the hardware fifo or something in the
>driver itself.
OK, I think we found the issue!
http://www.freebsd.org/cgi/query-pr.cgi?pr=121421
Not sure if the semantics are exactly right, but adding
hint.uart.0.flags="0x100"
hint.uart.1.flags="0x100"
hint.uart.2.flags="0x100"
hint.uart.3.flags="0x100"
to device.hints fixed the issue!
The next question-- is there a way to do this with the ucom driver as
well ? We are seeing the same issue with it.
---Mike
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