Regarding MPC8540 IRQ Issue

Bhupender Saharan bhupi.saharan at gmail.com
Sun Jun 17 10:16:42 EST 2007


Hi Sudhir,

>From the PCI dump it looks like IRQ PIN register is 0. During enumeration
when BIOS sees that IRQ PIN register is 0, it would not allocate any
interrupt for this card and that's why you are seeing IRQ Line register also
as 0 value.

We need to do some work around for this.

 IN the driver you need to register for all the pci vectors( INTA,B,C and
D). You would be called for any interrupt happening on the bus. you have to
check if the interrupt is for you and then claim it otherwise return that
interrupt is not for you.


Regards
Bhupi


On 6/16/07, sudheer <urwithsudheer at gmail.com> wrote:
>
> Hello All
>
> I am working on MPC8540 board placing it in the PCI slot of the x86
> system.
> After system bootup , i could see the powerpc board detected and pci
> config space configured.
> But i could not find any IRQ assigned for it.
>
> SetUp:
> Host: x86 System- Linux-2.6.9
> HOST PCI Slot is 64-bit, 66MHz
> Agent: MPC8540 Board.
>
> Here is dump of "lspci -vx " for this device.
>
> 04:03.0 Power PC: Motorola MPC8540 (rev 20) (prog-if 01)
>         Flags: bus master, 66Mhz, fast devsel, latency 64
>         Memory at dee00000 (32-bit, non-prefetchable) [size=1M]
>         Capabilities: [60] #00 [0000]
> 00: 57 10 08 00 46 01 b0 00 20 01 20 0b 00 40 00 00
> 10: 00 00 e0 de 00 00 00 00 00 00 00 00 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 30: 00 00 00 00 60 00 00 00 00 00 00 00 00 00 00 00
>
> From the above dump - IRQ Pin & Line of config space shows zeroes.
>
> I tried writing a small module and probing for IRQ generating a message
> interrupt. Though i could see in the 8540 message status register that
> interrupt is generated, i could not get any IRQ when i do the probe. For
> this trial,  i have configured the PIC message enable register, message
> vector/priority and destination registers, processor current task
> priority register (CPTR).
>
> Can anyone give me some suggestions to try out.
>
> Thanks
> Sudheer
>
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