From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michel Lanners Message-Id: <199909011613.SAA02982@mcp.cpu.lu> Subject: Re: vger-2.3.16 on pmac To: costabel@wanadoo.fr (Martin Costabel) Date: Wed, 01 Sep 1999 18:13:16 METDST Cc: linuxppc-dev@lists.linuxppc.org In-Reply-To: <37CD0CE1.9A2BC014@wanadoo.fr>; from "Martin Costabel" at Sep 01, 99 1:24 pm Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Hi martin, > I had, however, to apply one hack to make my ethernet card work: The new > (certainly not quite finished) pci code gives it a wrong IRQ number. And > this is something I would like to understand: > > There are 2 different IRQs for a given PCI card. If I do a 'lspci -v', I > get the one that is actually used and shows up in /proc/interrupts and > also in the boot messages, like for me The one is the interrupt number in the PCI config register on the device, which is plain bogus (as I understand it). The other IRQ, in your case 25, is assigned by OpenBugware upon system boot, and reported in the device tree's properties (can't remenber which one right now; have a look at /proc/device-tree). > If I do a 'lspci -v -b', I get another one, in this case IRQ160. This > one is also in the memory at /proc/bus/pci/devices, or in 'lspci -vx', > where I see a0=160. i.e. in PCI config space. That's the (unchanged) bogus value. > This, at least, was the situation before 2.3.15-final. Now the unpatched > 2.3.15-final or 2.3.16-final (with trivial patches to make it compile) > give me a boot message with IRQ160 and 'lspci -v' and 'lspci -v -b' both > give the same value 160. This is not a valid interrupt number, and of > course the card does not work. That means that the patch I made for the PCI fixup code isn't in those versions. I'm not at my machine right now; once at home, I'll see if I get a chance to put it on my web page. > My question is: At what place in the kernel is (or used to be) the > bus-centered IRQ160 translated into the cpu-centered IRQ25? There's no translation per se; it's done in the pci_bios_fixup() routine in arch/ppc/kernel/pmac_pci.c. > My hack was to put some 'if (irq == 160) irq=25;' somewhere in > pmac_setup.c, like in chrp_setup.c, where IRQ2 is translated into IRQ9. > This works (I am writing this using it) and it shows that there is > really not much wrong otherwise with the pci code (at least not for the > devices in my machine). That's not the best place for the fix, but the effect is the same ;-). Michel ----------------------------------- .signature left at home [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. Please check http://lists.linuxppc.org/ ]] [[ and http://www.linuxppc.org/ for useful information before posting. ]]