Date: Thu, 9 Nov 2000 13:31:46 -0500 (EST) From: Keith Warno Message-ID: Subject: Re: [SLE] IRQ sharing With modern motherboards and the bazillion peripherals that one can use in his/her PC, IRC sharing virtually a necessity. I believe motherboards and BIOSs are designed to handle IRQ sharing on the PCI bus in order to talk to the bazillion peripherals. Whether or not it's "standard", I have no clue. :) If you are unfortunate enough to be dual-booting linux and winblows 9x, the next time you are bowing down to Big Bad Bill, check out the device manager and you may see some blurb about "blah blah for PCI steering". Common sense suggests this has something to do w/ IRQ sharing. As a footnote, both my SCSI controller and my video card are on the same IRQ, and the machine hasn't exploded (yet). :) Bus 0, device 13, function 0: SCSI storage controller: Adaptec AIC-7860 (rev 3). Medium devsel. Fast back-to-back capable. IRQ 11. Master Capable. Latency=64. Min Gnt=4.Max Lat=4. I/O at 0x1000 [0x1001]. Non-prefetchable 32 bit memory at 0xf4000000 [0xf4000000]. Bus 1, device 0, function 0: VGA compatible controller: 3Dfx Unknown device (rev 1). Vendor id=121a. Device id=5. Fast devsel. Fast back-to-back capable. IRQ 11. Non-prefetchable 32 bit memory at 0xf6000000 [0xf6000000]. Prefetchable 32 bit memory at 0xfc000000 [0xfc000008]. I/O at 0x9000 [0x9001]. Regards, kw On 2000-11-09 at 14:54 -0200, Flavio Arthur Leal Ferreira uttered: | | I installed two RealTek PCI network cards in a firewall box. | Both cards are using IRQ 10. | It is working. | I don't understand how irq sharing works. | I had read something about optional support to irq sharing with serial | ports. | But with PCI bus, is it standard? Does it impact performance? | I didn't find any information in pci-howto. Can anybody give some hints? | | Thanks.