Hi, i have developed a driver for my legacy multiport serial ISA card,it has a PC16550D chip. In that driver,i call register_serial() to register my drivers presence. The problem is that when i tested the driver using minicom,communication is very very slow. I have read the Interrupt problems from tldp.org site.When i put my driver in polling mode (using setserial irq 0),the communication has become very fast. So i arrived at a conclusion that IRQ has some problem. My boards IRQ is 9 and it is shared between both the port of PC16550D. 1. Whether serial.c of linux kernel 2.4.20-20.9 ,support IRQ sharing on ISA cards? 2. Do i need to have seperate IRQ handlers in my driver other that one already in serial.c ? Any ideas ? Thanks in advance LG _______________________________________________ Redhat-devel-list mailing list Redhat-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/redhat-devel-list