Messages in this thread | | | Date | Mon, 14 Feb 2000 23:01:47 -0500 | Subject | Re: char/Serial.c | From | tytso@mit ... |
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Date: Mon, 14 Feb 2000 13:16:02 -0500 From: Uncle George <gatgul@voicenet.com>
Apparently my ttyS1 had an IRQ if 5 ( rather than the usual setting of IRQ 3 ). It seems that the serial driver does not really detect the IRQ settings at all . Without the proper IRQ settings, the port simply times out, and does the next chunk of chars. Very slow, and chunks/fifo fills are also not (always) in multiples of 16.
My IRQ settings for ttyS2 & ttyS3 are not what serial.c expects as 4 & 3 respectively ( i use 5 & 9 ), but the log in var/log/messages say thet they were detected/set as 4 & 3.
This failure to detect the port IRQ's seems to be a boo boo. Do I get to annoy the last serial.c maintainer ( if there is still one )
You can configure the irq's using the "setserial" command. You can also try to autodetect the irq's using the setserial command, but on some hardware platforms the autodetection fails, and leaves you with the irq's set to zero.
I used to try to make IRQ autodetection work, but it turned out to be causing more failures than it saved, due to the fact that PC hardware manufacturer's are unbearably sloppy about implementing everything under them.
- Ted
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