MPC5200Lite PCI & IRQ

MPC5200Lite PCI & IRQ

[Bertrand Baudet]

Hi,

I'm trying to plug a sata card in the PCI slot of the MPC5200Lite.

I'm using DENX linuxppc_2_4_devel CVS tree.


The INTA of the PCI bus is connected to the IRQ0 of the MPC5200.
In mpc5xxx.h IRQ0 is defined a 0:
#define MPC5xxx_CRIT_IRQ_BASE		0
#define MPC5xxx_IRQ0               (MPC5xxx_CRIT_IRQ_BASE + 0)

By default the IRQ line of the sata card is 0, so I don't have to set it
to another IRQ number under U-Boot.

>From the source code, it looks like a value 0 for the IRQ means the IRQ
is
disabled.

>From "drivers/ide/ide-probe.c", in the 'hwif_init' function:
...
if (!hwif->irq) {
   if (!(hwif->irq = ide_default_irq(hwif->io_ports[IDE_DATA_OFFSET])))
   {
      printk("%s: DISABLED, NO IRQ\n", hwif->name);
      return (hwif->present = 0);
   }
}
...

Commenting out the above code allow the PCI card to run properly.


Then I changed the IRQ0 to 1 by increasing the critical IRQ base value:
#define MPC5xxx_CRIT_IRQ_BASE		1
#define MPC5xxx_IRQ0               (MPC5xxx_CRIT_IRQ_BASE + 0)
and remove my comment around the above code (clean source).

By placing the interrupt line to 1 I was able to get the PCI card
to run properly.

I rather change the default critical IRQ base but I was wondering if
this
could have some bad effect somewhere else in the code?



Has anybody tried to plug a PCI card on the PCI slot of the MPC5200 and
have
the same issue?



Regards,
Bertrand

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Re: MPC5200Lite PCI & IRQ

[Wolfgang Denk]

In message <5A96167EBCEA8440A48790B5419953AE13C443@gr-lafayette.lacie.com> you wrote:
>
> Has anybody tried to plug a PCI card on the PCI slot of the MPC5200 and

Yes.

> have
> the same issue?

No. We didn't try any kind of IDE controller yet, though.

Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
But it's real. And if it's real it can be affected ... we may not  be
able  to break it, but, I'll bet you credits to Navy Beans we can put
a dent in it.
	-- deSalle, "Catspaw", stardate 3018.2

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Re: MPC5200Lite PCI & IRQ

[David Woodhouse]

On Fri, 2004-06-04 at 15:00 +0200, Bertrand Baudet wrote:
> Hi,
>
> I'm trying to plug a sata card in the PCI slot of the MPC5200Lite.
...
> By default the IRQ line of the sata card is 0,
...
> From the source code, it looks like a value 0 for the IRQ means the IRQ
> is disabled.
>
> From "drivers/ide/ide-probe.c", in the 'hwif_init' function:
> ...
> if (!hwif->irq) {
>    if (!(hwif->irq = ide_default_irq(hwif->io_ports[IDE_DATA_OFFSET])))
>    {
>       printk("%s: DISABLED, NO IRQ\n", hwif->name);
>       return (hwif->present = 0);
>    }
> }
> ...
>
> Commenting out the above code allow the PCI card to run properly.

This is a bug in the IDE driver. Zero is a perfectly valid IRQ number --
I have boxes where PCI slots get IRQ #0 too. Please fix the IDE driver
and send the patch to the IDE maintainer.

--
dwmw2


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