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 <adet...@br.ibm.com>
Signed-off-by: Michael Ellerman <mich...@ellerman.id.au>
Index: linux-2.6/arch/powerpc/platforms/pseries/msi.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/pseries/msi.c 2009-11-04
06:35:39.000000000 -0700
+++ linux-2.6/arch/powerpc/platforms/pseries/msi.c 2009-11-04
07:23:27.000000000 -0700
@@ -432,8 +432,6 @@ static int rtas_setup_msi_irqs(struct pc
/* Read config space back so we can restore after reset */
read_msi_msg(virq, &msg);
entry->msg = msg;
-
- unmask_msi_irq(virq);
}
return 0;
Index: linux-2.6/arch/powerpc/platforms/pseries/xics.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/pseries/xics.c 2009-11-04
06:35:39.000000000 -0700
+++ linux-2.6/arch/powerpc/platforms/pseries/xics.c 2009-11-04
07:23:27.000000000 -0700
@@ -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
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;
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