Hi.
I found & fixed a problem with #PIRQD line setup for VIA PCI IRQ
router. Kernel was not able to receive any interrupts from network card,
which PCI slot IRQ pin A was routed to PIRQ line D of VIA PCI IRQ
router. According to VIA specs, PIRQ D routing is out of standard
'nibble' scheme.
I tested patch with 2.4.20 kernel, it can be applied to 2.4.22-pre2 as
well.
Thanks to my employer (Phoenix Technologies) who kindly allowed me to
make this patch public.
Aleks.
===== arch/i386/pci/irq.c 1.25 vs edited =====
--- 1.25/arch/i386/pci/irq.c Thu Jun 19 17:58:11 2003
+++ edited/arch/i386/pci/irq.c Thu Jul 3 19:49:14 2003
@@ -196,15 +196,16 @@
/*
* The VIA pirq rules are nibble-based, like ALI,
* but without the ugly irq number munging.
+ * However, PIRQD is in the upper instead of lower 4 bits.
*/
static int pirq_via_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
{
- return read_config_nybble(router, 0x55, pirq);
+ return read_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq);
}
static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
{
- write_config_nybble(router, 0x55, pirq, irq);
+ write_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq, irq);
return 1;
}
> If you don't mind, I would prefer the attached patch, which is a
little
> bit less verbose.
Sure I don't :)
> I will make sure this fix is merged into 2.4 and 2.5, if noone beats
me
> to it.
Thanks.
Aleks.
>
> static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
> {
> - write_config_nybble(router, 0x55, pirq, irq);
> + write_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq, irq);
> return 1;
> }
you missed the
> + return (x >> 4);
in the original patch... so your code is NOT identical.
Arjan van de Ven wrote:
>>
>> static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
>> {
>>- write_config_nybble(router, 0x55, pirq, irq);
>>+ write_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq, irq);
>> return 1;
>> }
>
>
>
> you missed the
>
>>+ return (x >> 4);
>
> in the original patch... so your code is NOT identical.
Look at read_config_nybble...
return (nr & 1) ? (x >> 4) : (x & 0xf);
Can you spell out which part is different? I don't see it.
Jeff
On Fri, 4 Jul 2003, Arjan van de Ven wrote:
>
> >
> > static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
> > {
> > - write_config_nybble(router, 0x55, pirq, irq);
> > + write_config_nybble(router, 0x55, pirq == 4 ? 5 : pirq, irq);
> > return 1;
> > }
>
>
> you missed the
> > + return (x >> 4);
> in the original patch... so your code is NOT identical.
It's ok :
nybble(0x57, 1) == nybble(0x55, 5)
- Davide