On Sun, 15 Aug 1999, Michel Lanners wrote:

quoted

quoted

- The IRQ fixup code already checks for the presence of interrupts, so
I'v changed Martin's comment. Also, I'm not sure if PMac PCI boards can
ever use more than one interrupt, as all PCI interrupt lines are OR'ed
together on the bridge....

   If they really are, just kill the whole comment, it's bogus.

OK, I'll do that. Paul, any idea whether the IRQ OR'ing is done on the
MPC106 as well? Geert, what about your board?

On the LongTrail, interrupts are controlled by the OpenPIC in the Hydra Mac
I/O. This OpenPic has 20 inputs, of which 6 are used by PCI (asm-ppc/hydra.h):

#define HYDRA_INT_EXT1          12      /* PCI IRQW */
#define HYDRA_INT_EXT2          13      /* PCI IRQX */
#define HYDRA_INT_EXT3          14      /* PCI IRQY */
#define HYDRA_INT_EXT4          15      /* PCI IRQZ */
#define HYDRA_INT_EXT5          16      /* IDE Primay/Secondary */
#define HYDRA_INT_EXT6          17      /* IDE Secondary */

FYI, input 0 is used for the legacy ISA cascade.

IRQ[W-Z] are wired to INT #A-D in the 4 PCI slots using the standard interrupt
line rotating technique. Full schematics at
ftp://ftp.austin.ibm.com/pub/PPC_support/reference_designs/longtrail/ :-)

The IDE interrupts are wired to the interrupt lines on the W83C553 PCI/ISA+IDE.

quoted

   No driver should touch PCI_INTERRUPT_LINE at all. If it does,
it's buggy and should be fixed instead of working around it in generic
PCI code. The only correct way how to get the interrupt number is to
look at pci_dev->irq (on some architectures, the interrupt numbers
are too large to fit in the interrupt line configuration register).

OK, then I'll only update pci_dev->irq. We'll see if any driver
breaks ;-)

On the LongTrail (and other PPC boxes with OpenPIC), pci_dev->irq is changed by
the PCI fixup code since interrupts 1-16 are mapped to the legacy ISA
interrupts for compatibility reasons, while 17-36 are the 20 OpenPIC
interrupts.

Greetings,

						Geert

--
Geert Uytterhoeven                     Geert.Uytterhoeven@cs.kuleuven.ac.be
Wavelets, Linux/{m68k~Amiga,PPC~CHRP}  http://www.cs.kuleuven.ac.be/~geert/
Department of Computer Science -- Katholieke Universiteit Leuven -- Belgium


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