Date: Mon, 10 Dec 2001 14:45:02 -0800 From: Mike Smith <msmith@freebsd.org> To: Bernd Walter <ticso@cicely8.cicely.de> Cc: Danny Braniss <danny@cs.huji.ac.il>, Mike Smith <msmith@FreeBSD.ORG>, freebsd-hackers@FreeBSD.ORG, msmith@mass.dis.org Subject: Re: irq Message-ID: <200112102245.fBAMj2V03977@mass.dis.org> In-Reply-To: Message from Bernd Walter <ticso@cicely8.cicely.de> of "Mon, 10 Dec 2001 21:59:05 %2B0100." <20011210215905.E11774@cicely8.cicely.de>
next in thread | previous in thread | raw e-mail | index | archive | help
> A PCI slot has 4 irq lines named INTA to INTD. > On PCs all slots share the same 4 physical irqs and the lines are > hardwired on the board in alternating order to each slot. Not necessarily. This is the classic barber-pole or "PCI swizzle"; it's not mandated for motherboard designs though (but it is for bridges, since bridges have no other interrupt routing metadata). > If you want cards not to share irqs you have to swap slots until you > get what you want - you can't enforce it with software. This is closer to correct, though still not universally so. Better just to say that PCI interrupt routing is weird, and leave it at that. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200112102245.fBAMj2V03977>