On Fri, 2007-05-11 at 13:26 -0700, David Miller wrote: > Hi Michael, I'm still working through the various regressions on > sparc64 added by your MSI changes :-)
Hi Dave,
Guilty as charged - I did CC you on the patches though ;)
> The one I fixed the other day was a missed switch over to
> alloc_pci_dev() in the sparc64 PCI probing code which caused an OOPS
> in pci_enable_msi() because the list head of the pci dev was not
> initialized. PowerPC's OBP firmware tree based PCI probing code
> was updated, sparc64's wasnt.
Sorry - not sure how I missed that one, it even matches
"k.alloc(.*pci_dev" - thanks for fixing it :)
> Today's find is a triggered assertion in msi_free_irqs() when the
> system doesn't support MSI, in which case arch_setup_msi_irqs() always
> returns an error.
What do you need to determine that the system can't support MSI? Could
you do that logic in arch_msi_check_device()?
> The problem is that when this happens we branch into msi_free_irqs(),
> to which you added the following assertion loop:
>
> list_for_each_entry(entry, &dev->msi_list, list)
> BUG_ON(irq_has_action(entry->irq));
>
> Well, if arch_setup_msi_irqs() fails, entry->irq will be zero and
> although that's never assigned to any normal devices we use that IRQ
> number for the timer interrupt on sparc64 so this assertion triggers.
>
> Better to test for zero before doing the irq_has_action() assertion
> thing.
Yep, looks good - it matches the logic in arch_teardown_msi_irqs().
cheers
Acked-by: Michael Ellerman <[EMAIL PROTECTED]>
> Signed-off-by: David S. Miller <[EMAIL PROTECTED]>
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index e6740d1..d9cbd58 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -549,8 +549,10 @@ static int msi_free_irqs(struct pci_dev* dev)
> {
> struct msi_desc *entry, *tmp;
>
> - list_for_each_entry(entry, &dev->msi_list, list)
> - BUG_ON(irq_has_action(entry->irq));
> + list_for_each_entry(entry, &dev->msi_list, list) {
> + if (entry->irq)
> + BUG_ON(irq_has_action(entry->irq));
> + }
>
> arch_teardown_msi_irqs(dev);
>
--
Michael Ellerman
OzLabs, IBM Australia Development Lab
wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)
We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person
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