Messages in this thread |  | | | Date | Thu, 29 Jan 1998 01:33:57 -0800 | | From | Ian Eure <> | | Subject | Re: IRQ 255? |
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Does anyone know what the advantages/disadvantages of having an irq for a video card are?
Pawel S. Veselov wrote:
> Hello, Bernhard! > > On Tue, 27 Jan 1998, Bernhard Rosenkraenzer wrote: > > >> Bus 0, device 2, function 0: > >> VGA compatible controller: Cirrus Logic GD 7548 (rev 0). > >> Fast devsel. IRQ 255. > >> > >> Note that the video device is on IRQ 255. Is this possibly a bug somewhere? > > > >IRQ 255 doesn't exist, but it looks like a (unsigned char) -1. > >My guess is that your VGA card doesn't use an IRQ, and IRQ 255 is the PCI > >driver's way to display this. > > PCI controller sets -1 ( 255 ) IRQ in two cases : > a) The PCI device doesn't need an IRQ. > b) There is no available IRQ to assign to this device. > > Bye. > -- > Natural laws have no pity. > > -- > With best of best regards, Pawel S. Veselov (aka Black Angel) > internet : vps@unicorn.niimm.spb.su ( mail,finger,talk ) > Web page : http://www.niimm.spb.su/~vps/ > ICQ : 5252265
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