MPC7448_HPC2 question

MPC7448_HPC2 question

[Benjamin Herrenschmidt]

Any reason why that:

void mpc7448_hpc2_fixup_irq(struct pci_dev *dev)
{
	struct pci_controller *hose;
	struct device_node *node;
	const unsigned int *interrupt;
	int busnr;
	int len;
	u8 slot;
	u8 pin;

	/* Lookup the hose */
	busnr = dev->bus->number;
	hose = pci_bus_to_hose(busnr);
	if (!hose)
		printk(KERN_ERR "No pci hose found\n");

	/* Check it has an OF node associated */
	node = (struct device_node *) hose->arch_data;
	if (!node)
		printk(KERN_ERR "No pci node found\n");

	interrupt = get_property(node, "interrupt-map", &len);
	slot = find_slot_by_devfn(interrupt, dev->devfn);
	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
	if (pin == 0 || pin > 4)
		pin = 1;
	pin--;
	dev->irq  = interrupt[slot*4*7 + pin*7 + 5];
	DBG("TSI_PCI: dev->irq = 0x%x\n", dev->irq);
}

Cannot be replaced by:

	pci_read_irq_line(dev);

I'm about to make pci_read_irq_line() called by default by the PCI
code (with a new ppc_md.pci_irq_fixup for platforms that really need
something else done) and so while "fixing" all platforms, I stumbled
accross the code above which is a bit shocking :)

Cheers,

Ben.

Re: MPC7448_HPC2 question

[Zang Roy-r61911]

On Wed, 2006-10-25 at 13:20, Benjamin Herrenschmidt wrote:
> Any reason why that:
> 
> void mpc7448_hpc2_fixup_irq(struct pci_dev *dev)
> {
>         struct pci_controller *hose;
>         struct device_node *node;
>         const unsigned int *interrupt;
>         int busnr;
>         int len;
>         u8 slot;
>         u8 pin;
> 
>         /* Lookup the hose */
>         busnr = dev->bus->number;
>         hose = pci_bus_to_hose(busnr);
>         if (!hose)
>                 printk(KERN_ERR "No pci hose found\n");
> 
>         /* Check it has an OF node associated */
>         node = (struct device_node *) hose->arch_data;
>         if (!node)
>                 printk(KERN_ERR "No pci node found\n");
> 
>         interrupt = get_property(node, "interrupt-map", &len);
>         slot = find_slot_by_devfn(interrupt, dev->devfn);
>         pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
>         if (pin == 0 || pin > 4)
>                 pin = 1;
>         pin--;
>         dev->irq  = interrupt[slot*4*7 + pin*7 + 5];
>         DBG("TSI_PCI: dev->irq = 0x%x\n", dev->irq);
> }
> 
> Cannot be replaced by:
> 
>         pci_read_irq_line(dev);
> 
> I'm about to make pci_read_irq_line() called by default by the PCI
> code (with a new ppc_md.pci_irq_fixup for platforms that really need
> something else done) and so while "fixing" all platforms, I stumbled
> accross the code above which is a bit shocking :)
> 
> Cheers,
> 
> Ben.
> 
> 
> 

Ben, 
	Last week, I had tried to do the replacement. While, it did not work. I
had though some update of pci_read_irq_line() should be needed.
	Any way, I will investigate it and give the patch ASAP :-).

Roy

Re: MPC7448_HPC2 question

[Zang Roy-r61911]

On Wed, 2006-10-25 at 13:20, Benjamin Herrenschmidt wrote:

> 
> Cannot be replaced by:
> 
>         pci_read_irq_line(dev);

When I use pci_read_irq_line(), the pci interrupt number exceeds the
limit of mpic-> irq_count. my mpic->irq_count = 0x18, which is gotten
from on chip register. 

mpic_host_map() can not return successful value.

Roy

Re: MPC7448_HPC2 question

[Benjamin Herrenschmidt]

On Wed, 2006-10-25 at 17:31 +0800, Zang Roy-r61911 wrote:
> On Wed, 2006-10-25 at 13:20, Benjamin Herrenschmidt wrote:
> 
> > 
> > Cannot be replaced by:
> > 
> >         pci_read_irq_line(dev);
> 
> When I use pci_read_irq_line(), the pci interrupt number exceeds the
> limit of mpic-> irq_count. my mpic->irq_count = 0x18, which is gotten
> from on chip register. 
> 
> mpic_host_map() can not return successful value.

That is not normal... Something must be wrong with your code or your
DT... can you get more details about what precisely is happening in both
cases ?

Ben.

Re: MPC7448_HPC2 question

[Zang Roy-r61911]

On Wed, 2006-10-25 at 21:45, Benjamin Herrenschmidt wrote:
> On Wed, 2006-10-25 at 17:31 +0800, Zang Roy-r61911 wrote:
> > On Wed, 2006-10-25 at 13:20, Benjamin Herrenschmidt wrote:
> > 
> > > 
> > > Cannot be replaced by:
> > > 
> > >         pci_read_irq_line(dev);
> > 
> > When I use pci_read_irq_line(), the pci interrupt number exceeds the
> > limit of mpic-> irq_count. my mpic->irq_count = 0x18, which is
> gotten
> > from on chip register. 
> > 
> > mpic_host_map() can not return successful value.
> 
> That is not normal... Something must be wrong with your code or your
> DT... can you get more details about what precisely is happening in
> both
> cases ?
> 
> Ben.
> 

I think I have gotten the point. For tsi108/9, there are 24 internal
interrupt. PCI/INTA  to PCI/INTD are routed to interrupt 23 with a
special mechanism on the chip. INTA to INTD are assiged to nubmer 36 to
39, which are exceed the nubmer irq number assigned in mpic_alloc().
This cause abnormal return in function pci_read_irq_line().
I have worked out a patch. after a test, I will publish it.
Roy