From 8435b027b87a78145992c37b0b8ed0f1b7761bf0 Mon Sep 17 00:00:00 2001
From: Andre Detsch <adetsch@br.ibm.com>
Date: Wed, 4 Nov 2009 13:03:19 -0200
Subject: [PATCH] powerpc/pci: Fix regression in powerpc MSI-X
Patch f598282f5145036312d90875d0ed5c14b49fd8a7 exposed a problem in
powerpc MSI-X functionality, making network interfaces such as ixgbe
and cxgb3 stop to work when MSI-X is enabled. RX interrupts were not
being generated.
The problem was caused because MSI irq was not being effectively
unmasked after device initialization.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/platforms/pseries/msi.c | 2 --
arch/powerpc/platforms/pseries/xics.c | 9 +++++++++
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index bf2e1ac41308e..1164c3430f2c5 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -432,8 +432,6 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
/* Read config space back so we can restore after reset */
read_msi_msg(virq, &msg);
entry->msg = msg;
-
- unmask_msi_irq(virq);
}
return 0;
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index 419f8a637ffe5..b9bf0eedccf27 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -18,6 +18,7 @@
#include <linux/init.h>
#include <linux/radix-tree.h>
#include <linux/cpu.h>
+#include <linux/msi.h>
#include <linux/of.h>
#include <asm/firmware.h>
@@ -219,6 +220,14 @@ static void xics_unmask_irq(unsigned int virq)
static unsigned int xics_startup(unsigned int virq)
{
+ /*
+ * The generic MSI code returns with the interrupt disabled on the
+ * card, using the MSI mask bits. Firmware doesn't appear to unmask
+ * at that level, so we do it here by hand.
+ */
+ if (irq_to_desc(virq)->msi_desc)
+ unmask_msi_irq(virq);
+
/* unmask it */
xics_unmask_irq(virq);
return 0;
--
GitLab