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>
---
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!
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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