1 files changed, 81 insertions, 0 deletions

diff --git a/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.9/0056-genirq-Unmask-oneshot-irqs-when-thread-was-not-woken.patch b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.9/0056-genirq-Unmask-oneshot-irqs-when-thread-was-not-woken.patch
new file mode 100644
index 00000000..1dc0bbbf
--- /dev/null
+++ b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.9/0056-genirq-Unmask-oneshot-irqs-when-thread-was-not-woken.patch
@@ -0,0 +1,81 @@
+From fb8f89c9c078476af3cda9f2373b5dc72cfc3ead Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Tue, 7 Feb 2012 17:58:03 +0100
+Subject: [PATCH 56/72] genirq: Unmask oneshot irqs when thread was not woken
+
+commit ac5637611150281f398bb7a47e3fcb69a09e7803 upstream.
+
+When the primary handler of an interrupt which is marked IRQ_ONESHOT
+returns IRQ_HANDLED or IRQ_NONE, then the interrupt thread is not
+woken and the unmask logic of the interrupt line is never
+invoked. This keeps the interrupt masked forever.
+
+This was not noticed as most IRQ_ONESHOT users wake the thread
+unconditionally (usually because they cannot access the underlying
+device from hard interrupt context). Though this behaviour was nowhere
+documented and not necessarily intentional. Some drivers can avoid the
+thread wakeup in certain cases and run into the situation where the
+interrupt line s kept masked.
+
+Handle it gracefully.
+
+Reported-and-tested-by: Lothar Wassmann <lw@karo-electronics.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/irq/chip.c |   25 +++++++++++++++++++++++--
+ 1 file changed, 23 insertions(+), 2 deletions(-)
+
+diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
+index f7c543a..b742edc 100644
+--- a/kernel/irq/chip.c
++++ b/kernel/irq/chip.c
+@@ -330,6 +330,24 @@ out_unlock:
+ }
+ EXPORT_SYMBOL_GPL(handle_simple_irq);
+ 
++/*
++ * Called unconditionally from handle_level_irq() and only for oneshot
++ * interrupts from handle_fasteoi_irq()
++ */
++static void cond_unmask_irq(struct irq_desc *desc)
++{
++       /*
++        * We need to unmask in the following cases:
++        * - Standard level irq (IRQF_ONESHOT is not set)
++        * - Oneshot irq which did not wake the thread (caused by a
++        *   spurious interrupt or a primary handler handling it
++        *   completely).
++        */
++       if (!irqd_irq_disabled(&desc->irq_data) &&
++           irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot)
++               unmask_irq(desc);
++}
++
+ /**
+  *     handle_level_irq - Level type irq handler
+  *     @irq:   the interrupt number
+@@ -362,8 +380,8 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
+ 
+        handle_irq_event(desc);
+ 
+-       if (!irqd_irq_disabled(&desc->irq_data) && !(desc->istate & IRQS_ONESHOT))
+-               unmask_irq(desc);
++       cond_unmask_irq(desc);
++
+ out_unlock:
+        raw_spin_unlock(&desc->lock);
+ }
+@@ -417,6 +435,9 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
+        preflow_handler(desc);
+        handle_irq_event(desc);
+ 
++       if (desc->istate & IRQS_ONESHOT)
++               cond_unmask_irq(desc);
++
+ out_eoi:
+        desc->irq_data.chip->irq_eoi(&desc->irq_data);
+ out_unlock:
+-- 
+1.7.9.4
+