Messages in this thread | | | Date | Wed, 2 Nov 2005 16:13:50 -0500 | Subject | Re: No sharing IRQ broken board problem | From | (Lennart Sorensen) |
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On Wed, Nov 02, 2005 at 09:06:53PM +0000, tcrix@att.net wrote: > I have a pci board in development that works but.. > it can not share the interrupt line. > > Has someone hacked through the problem of reserving one of the inta, intb, .. 's for a single device? I would love to see how you did so I could continue on with my driver while I wait for the !@$#!@ hardware guys to fix the board.
As far as I understand the PCI specs, your device is currently NOT a PCI device.
Support for shared IRQs on PCI is as far as I can tell not optional. Short of designing your own mainboard there is no way to prevent the interrupt lines from being joined. One one board I use there are 6 PCI devices, with 3 on INT-A and 3 on INT-B (The SBC doesn't have INT-C and INT-D). On my desktop machine, INT A is the same on slot 1 and 5, 2, and 6 and onyl 3 and 4 have INT-A to themselves. Of course this doesn't prevent the bios from assigning the same IRQ to INT-A on multiple sets as well. I have run a PPro some years ago with a single IRQ shared among all the PCI devices in the system. Neither linux nor windows had a problem with that and neither did any of the many PCI devices.
I think you are stuck waiting for the hardware guys to give you a PCI device that is really a PCI device. If you are lucky you can find one slot in your machine that doesn't share INT-A with any other PCI device, although on most modern machines there are so many PCI devices that it is imposible to find one that isn't shared.
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