This is a note to let you know that I've just added the patch titled
ARM: OMAP2+: INTC: Acknowledge stuck active interrupts
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-omap2-intc-acknowledge-stuck-active-interrupts.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 698b48532539484b012fb7c4176b959d32a17d00 Mon Sep 17 00:00:00 2001
From: Stefan Sørensen <stefan.sorensen@xxxxxxxxxxxxxxx>
Date: Thu, 6 Mar 2014 16:27:15 +0100
Subject: ARM: OMAP2+: INTC: Acknowledge stuck active interrupts
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From: Stefan Sørensen <stefan.sorensen@xxxxxxxxxxxxxxx>
commit 698b48532539484b012fb7c4176b959d32a17d00 upstream.
When an interrupt has become active on the INTC it will stay active
until it is acked, even if masked or de-asserted. The
INTC_PENDING_IRQn registers are however updated and since these are
used by omap_intc_handle_irq to determine which interrupt to handle,
it will never see the active interrupt. This will result in a storm of
useless interrupts that is only stopped when another higher priority
interrupt is asserted.
Fix by sending the INTC an acknowledge if we find no interrupts to
handle.
Signed-off-by: Stefan Sørensen <stefan.sorensen@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/mach-omap2/irq.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/arch/arm/mach-omap2/irq.c
+++ b/arch/arm/mach-omap2/irq.c
@@ -220,6 +220,7 @@ void __init ti81xx_init_irq(void)
static inline void omap_intc_handle_irq(void __iomem *base_addr, struct pt_regs *regs)
{
u32 irqnr;
+ int handled_irq = 0;
do {
irqnr = readl_relaxed(base_addr + 0x98);
@@ -247,8 +248,15 @@ out:
if (irqnr) {
irqnr = irq_find_mapping(domain, irqnr);
handle_IRQ(irqnr, regs);
+ handled_irq = 1;
}
} while (irqnr);
+
+ /* If an irq is masked or deasserted while active, we will
+ * keep ending up here with no irq handled. So remove it from
+ * the INTC with an ack.*/
+ if (!handled_irq)
+ omap_ack_irq(NULL);
}
asmlinkage void __exception_irq_entry omap2_intc_handle_irq(struct pt_regs *regs)
Patches currently in stable-queue which might be from stefan.sorensen@xxxxxxxxxxxxxxx are
queue-3.4/arm-omap2-intc-acknowledge-stuck-active-interrupts.patch
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