On 14 Aug 2001 12:40:12 +0100, J.A.Serralheiro wrote: > > Hi. A few months ago I posted here a few messages about a problem I had > sharing interrupts with serial ports. I had 2 srial ports in the main > board, and an old IO card in an ISA slot. > Well, it seems that the old io card was not able to share interrupts ( > main board usually do ), so I > made a very small board with some circuitry and attched it to the io card. > Now the card shares irqs 3, 4 and 7. I tested it with serial ports and > works > fine. I have the serial.o driver with SHARE_IRQ flag set. > What I want to know is how will the kernel behave if I assign irq 7 to > both parallel port and a serial port. The small board I made is very > flexible > by means of a set of jumpers. I can assign any irq ( 3,4 or 7) to a serial > port or the parallel port. Its fine that the serial driver is able to > share irqs. But parportpc.o and serial.o are diferent modules. How will > the irq share change the behaviour of these drivers? > > If the kernel allows the features im talking about, then, we'll have a > mutch more flexible way to add hardware to our system, without > constrains, if only manufacturers did with their cards what I did with > mine. > > PS: In my case performance loss is not a matter.
Do you have a device that requires the interrupt on the lpt ports? My understanding is that linux doesn't use the irq for just a printer. --mike
