Jonathan Sturges wrote:
>
> ----- Original Message ----
> From: Marc Jones <[EMAIL PROTECTED]>
> To: Jonathan Sturges <[EMAIL PROTECTED]>
> Cc: LinuxBIOS mailing list <linuxbios@linuxbios.org>
> Sent: Tuesday, September 25, 2007 12:05:19 PM
> Subject: Re: [LinuxBIOS] Two more CS5530 IRQ steering questions
>
>
>
> Jonathan Sturges wrote:
>>>> Jonathan Sturges wrote:
>>>> Two additional questions about CS5530 IRQ steering:
>>>> 1) Comments from Uwe Hermann and Peter Stuge have indicated that it's
>>>> really better for the kernel to setup the steering registers. Why is
>>>> this? It sounds like the BIOS is a good place to set these. I assume
>>>> that a knowledgeable OS could change them if necessary? At the very
>>>> least, it does sound like we all agree that it's OK to have LB setup the
>>>> steering until Linux is fixed.
>>>>
>>>> 2) Question about irq_tables.c. Many of the CS5536 systems have a
>>>> write_pirq_routing_table() in irq_tables.c that sets the steering
>>>> registers. I'd like to be able to set the steering registers in CS5530
>>>> systems too, but I'm not a software developer and I need some help. So in
>>>> src/mainboard/artecgroup/dbe61/irq_tables.c, you have:
>>>> /* Set up chipset IRQ steering. */
>>>> pciAddr = 0x80000000 | (CHIPSET_DEV_NUM << 11) | 0x5C;
>>>> chipset_irq_map = (PIRQD << 12 | PIRQC << 8 | PIRQB << 4 | PIRQA);
>>>> printk_debug("%s(%08X, %04X)\n", __FUNCTION__, pciAddr,
>>>> chipset_irq_map);
>>>> outl(pciAddr & ~3, 0xCF8);
>>>> outl(chipset_irq_map, 0xCFC);My main question with this block of code is
>>>> what the two outl() calls are for. It looks like pciAddr gets the address
>>>> of the 0x5c steering register, and chipset_irq_map sets the right bits to
>>>> set all 4 PIRQ lines. But I'd expect to see the chipset_irq_map written
>>>> to pciAddr.
>>>>
>>>> As an alternative, Kenji Noguchi used this code block to set the registers
>>>> in a CS5530 system he's working on (posted 5-May-2007):
>>>> device_t pdev;
>>>> //CS5530A
>>>> pdev = dev_find_slot(0, (0x12 << 3) + 0);
>>>> pci_write_config8(pdev, 0x5c, 0xab);
>>>> pci_write_config8(pdev, 0x5d, 0x09);
>>>>
>>>>
>>>> This block makes more sense to me. Obviously the register values could be
>>>> set by
>>>> #defines, but it looks simpler to me.
>>>>
>>>> Bottom line is, before I implement IRQ steering for my CS5530 system, I
>>>> want to understand what the first code block is doing, and if (or why)
>>>> it's preferable over the 2nd code block. Any guidance is appreciated.
>>>>
>>>> thanks,
>>>> Jonathan
>>>
>>>
>>> outl(pciAddr & ~3, 0xCF8);
>>> outl(chipset_irq_map, 0xCFC)
>>>
>>> is basically the same as
>>>
>>> pci_write_config8(pdev, 0x5c, 0xab);
>>> pci_write_config8(pdev, 0x5d, 0x09);
>>>
>>>
>>> CFC/CF8 is the PCI config space.
>> Ahhh... thanks Marc, that was the clarification I needed.
>>
>> With that in mind, that block of code should work directly with the CS5530
>> after defining CHIPSET_DEV_NUM appropriately. What about '0x80000000', is
>> that a common base address applicable to all CS553x systems?
>>
>> thanks,
>> Jonathan
>
> DEV_NUM should be a constant for the 5530. It is always hooked up on the
> same IDSEL. The 0x80000000 is standard for all i/o based PCI config
> accesses. It indicates that it is a config access and not just a normal
> PCI i/o access.
>
> Marc
>
>
>
> Marc,
> I've implemented the CS5536-style IRQ steering register code from above in my
> CS5530 system. This is what I'm using:
> /* Set up chipset IRQ steering. */
> pciAddr = 0x80000000 | (0x12 << 11) | 0x5C;
> chipset_irq_map = (PIRQD << 12 | PIRQC << 8 | PIRQB << 4 | PIRQA);
> printk_debug("%s(%08X, %04X)\n", __FUNCTION__, pciAddr,
> chipset_irq_map);
> outl(pciAddr & ~3, 0xCF8);
> outl(chipset_irq_map, 0xCFC);
>
> However, it doesn't seem to have worked entirely. If it had worked, I assume
> I should be able to boot a standard Linux kernel and have IRQs worked for the
> devices in the PIRQ table. Instead, these devices don't work, unless I boot
> a kernel with the CS5530 IRQ router patch.
> In the LB output, you get this from write_pirq_routing_table():
>
> write_pirq_routing_table(8000905C, 99BA)
>
> ...which I think is right. It doesn't seem like there's much that could be
> wrong here. Are the the steering bits reversed maybe? The high 8 bits are
> for PIRQD and C, so that would screw things up if they were written to 0x5C,
> which is the INTB/INTA register. Is there a reliable way to see the settings
> of the steering bits from a running system?
>
> thanks,
> Jonathan
>
Jonathan,
You can use lspci to get that information.
"lspci -xxxv" or "lspci -s 00:12.0 -xxxv" for just device 0x12
Marc
--
Marc Jones
Senior Firmware Engineer
(970) 226-9684 Office
mailto:[EMAIL PROTECTED]
http://www.amd.com/embeddedprocessors
--
linuxbios mailing list
linuxbios@linuxbios.org
http://www.linuxbios.org/mailman/listinfo/linuxbios
