From: wong@cs.tu-berlin.de (Wolfgang Jung) Subject: Re: ANS: ser. hang under X and QUES: login over serial Date: 18 Apr 1993 01:01:52 GMT
Daniel S. Ridge (newt@eng.umd.edu) wrote:
: I posted yesterday asking for help on my linux communications
: problems, and I had not realized that X didn't support IRQ sharing,
: and the mouse on com1 conflicted with the 2400 baud modem on com3
Since the serial IRQ handling is inside the kernel and is not
build into X. X just open the mouse port sets speed and afterwords
just reads from the FD(which points to (/dev/mouse))
So i would think the Problem lies in the IRQ Conflict on the
hardware where your Mouse Ports are getting Problems with your
Serial card. This is due to some vendors are building unsharable
IRQ lines, and this I thnik is the Problem here.
(Just take a look at the kernel source (kernel/chr_dev/serial.c)
there is the serial IRQ handling done. If the Hardware works
it is able to work with at least the four normal COM Ports
(with COM1 & 3 on IRQ 3 and COM2 & 4 on IRQ 4) Probably your Modems
or your Serialcard is not able to handle shared interups.
A soltion would be to put the Modems each on some own IRQ line,
Just check the hardware if you are with Open Colector or Totem Pole
IRQ Outputs ..
Gruss
Wolfgang