Here's a problem I already posted once, but stubornly remains: I have 4 serial ports. 2 on board and 2 in an old i/o adapter. The thing is that I cant have thenm both working at the same time. I know waht you r thinkg " use different irqs". I cant, I have none left.
port=/dev/ttySx Both ports work very nice, if there's only one (of them) receiving. The things I want to know are: Is there a way to configure the module serial.o to handle this problem? ofcourse assuming that this is NOT hardware matter. I am very confused because of this. According to some things I have read, if the uart tries to notify the interrupt handler, it will put 5V in the interrupt handler. Well, from the hardware " stand point", having 2 ports working one at a time, is the same having both working at the same time. I mean, If port1 wants to interrupt the cpu, it will put 5V in the int3. If port 3 is not trying to interrupt the cpu, it will put 0V, it works. Okay; Now if we reverse, port3 wants to interrupt and puts 5V, and ports 1 puts0V the thing still works . But having two programs trying to read from port1 and from port3 ( one program per port) just doens work. The only way this gives some output is when a simultaneous interrupts occurs on both ports. Can any one tell me how this may be solved? ( without probing each port? that looses bytes ). Because I really hate to buy hardware I cant fully use. serial.o reports IRQ_SHARE flag at boot up sincerely J.A.Serralheiro
