Messages in this thread | | | Date | Wed, 16 Aug 2006 16:57:38 +0200 | From | Raphael Hertzog <> | Subject | Re: How to avoid serial port buffer overruns? |
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On Wed, 16 Aug 2006, Lennart Sorensen wrote: > In my experience, the way to avoid overruns on a serial port was to use > a buffered serial port UART (such as a 16550A for example). I remember > my 486 wasn't reliable about 19200 or 38400 (depending on how busy the > cpu was) when using an 8250. Using a 16550A based card and I could do > 115200 without any issues since the UART had a 16 byte buffer to help > out the system. Unless your 386 has an add in card for the serial port, > it almost certainly has a very crappy UART and it would be very hard to > make it work reliably at higher speeds.
I forgot to mention the kind of UART in my mail but it is a 16650A (and configured as such and detected as such) and I have overruns nevertheless.
bash-2.05a# cat /proc/tty/driver/serial serinfo:1.0 driver revision: 0: uart:16550A port:000003F8 irq:4 tx:31 rx:7 RTS|CTS|DTR|DSR 1: uart:16550A port:000002F8 irq:3 tx:24 rx:7 RTS|CTS|DTR|DSR
(here there's no overrun but I almost didn't use the serial port since last reboot)
Cheers, -- Raphaël Hertzog
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