Commit 964a2996 authored Mar 03, 2011 by Nishanth Aravamudan Committed by Benjamin Herrenschmidt Mar 11, 2011

powerpc/pseries: Disable MSI using new interface if possible



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 <nacc@us.ibm.com>
Acked-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

parent 17b9f9e2

arch/powerpc/platforms/pseries/msi.c

+12 −2

Original line number	Diff line number	Diff line
		@@ -93,9 +93,19 @@ static void rtas_disable_msi(struct pci_dev *pdev)
		if (!pdn)
		return;

		if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0)
		/*
		* disabling MSI with the explicit interface also disables MSI-X
		*/
		if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) {
		/*
		* may have failed because explicit interface is not
		* present
		*/
		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)
		{