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Diffstat (limited to 'target/linux/brcm2708/patches-4.9/0006-irq-bcm2836-Prevent-spurious-interrupts-and-trap-the.patch')
-rw-r--r--target/linux/brcm2708/patches-4.9/0006-irq-bcm2836-Prevent-spurious-interrupts-and-trap-the.patch26
1 files changed, 26 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.9/0006-irq-bcm2836-Prevent-spurious-interrupts-and-trap-the.patch b/target/linux/brcm2708/patches-4.9/0006-irq-bcm2836-Prevent-spurious-interrupts-and-trap-the.patch
new file mode 100644
index 0000000000..3ebcb0a45f
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.9/0006-irq-bcm2836-Prevent-spurious-interrupts-and-trap-the.patch
@@ -0,0 +1,26 @@
+From 3fad09910dafeb93a351aefa90ca4fd490f68c84 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Fri, 4 Dec 2015 17:41:50 +0000
+Subject: [PATCH] irq-bcm2836: Prevent spurious interrupts, and trap them early
+
+The old arch-specific IRQ macros included a dsb to ensure the
+write to clear the mailbox interrupt completed before returning
+from the interrupt. The BCM2836 irqchip driver needs the same
+precaution to avoid spurious interrupts.
+
+Spurious interrupts are still possible for other reasons,
+though, so trap them early.
+---
+ drivers/irqchip/irq-bcm2836.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/drivers/irqchip/irq-bcm2836.c
++++ b/drivers/irqchip/irq-bcm2836.c
+@@ -175,6 +175,7 @@ __exception_irq_entry bcm2836_arm_irqchi
+ u32 ipi = ffs(mbox_val) - 1;
+
+ writel(1 << ipi, mailbox0);
++ dsb(sy);
+ handle_IPI(ipi, regs);
+ #endif
+ } else if (stat) {