On 03.03.2011 [11:39:23 -0800], Nishanth Aravamudan wrote:
> On upcoming hardware, we have a PCI adapter with two functions, one of
> which uses MSI and the other uses MSI-X. This adapter, when MSI is
> disabled using the "old" firmware interface (RTAS_CHANGE_FN), still
> signals an MSI-X interrupt and triggers an EEH. We are working with the
> vendor to ensure that the hardware is not at fault, but if we use the
> "new" interface (RTAS_CHANGE_MSI_FN) to disable MSI, we also
> automatically disable MSI-X and the adapter does not appear to signal
> any stray MSI-X interrupt.
>
> Signed-off-by: Nishanth Aravamudan <n...@us.ibm.com>
> Cc: Milton Miller <milt...@bga.com>
> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
> Cc: Paul Mackerras <pau...@samba.org>
Sorry, I fudged my git-send-email config, apologies that the Cc's above
weren't actually used in the original!
> ---
>
> This is effectively a PCI quirk, but I'm not sure how to do a
> architecture-specific quirk (looking through the code now). If anyone
> has any pointers, I'd appreciate it!
If this would be preferred, I think I see now how it would be done and
can work on a different patch that only makes this change for this
device.
Thanks,
Nish
> arch/powerpc/platforms/pseries/msi.c | 14 ++++++++++++--
> 1 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/msi.c
> b/arch/powerpc/platforms/pseries/msi.c
> index 1164c34..9434576 100644
> --- a/arch/powerpc/platforms/pseries/msi.c
> +++ b/arch/powerpc/platforms/pseries/msi.c
> @@ -93,8 +93,18 @@ static void rtas_disable_msi(struct pci_dev *pdev)
> if (!pdn)
> return;
>
> - if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0)
> - pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
> + /*
> + * disabling MSI with the explicit interface also disables MSI-X
> + */
> + if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) {
> + /*
> + * may have failed due to lacking
> + * "ibm,change-msix-capable" property
> + */
> + if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) {
> + pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
> + }
> + }
> }
>
> static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
> --
> 1.7.1
>
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--
Nishanth Aravamudan <n...@us.ibm.com>
IBM Linux Technology Center
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