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authorThomas Gleixner <tglx@linutronix.de>2014-02-15 00:55:19 +0000
committerThomas Gleixner <tglx@linutronix.de>2014-02-19 17:22:44 +0100
commita92444c6b2225a9115d661c950cb48a22aeace20 (patch)
treead76dd71c9fec1648469009cb356351ca23daef0 /kernel/irq/manage.c
parent18258f7239a61d8929b8e0c7b6d46c446459074c (diff)
downloadblackbird-op-linux-a92444c6b2225a9115d661c950cb48a22aeace20.tar.gz
blackbird-op-linux-a92444c6b2225a9115d661c950cb48a22aeace20.zip
genirq: Provide irq_wake_thread()
In course of the sdhci/sdio discussion with Russell about killing the sdio kthread hackery we discovered the need to be able to wake an interrupt thread from software. The rationale for this is, that sdio hardware can lack proper interrupt support for certain features. So the driver needs to poll the status registers, but at the same time it needs to be woken up by an hardware interrupt. To be able to get rid of the home brewn kthread construct of sdio we need a way to wake an irq thread independent of an actual hardware interrupt. Provide an irq_wake_thread() function which wakes up the thread which is associated to a given dev_id. This allows sdio to invoke the irq thread from the hardware irq handler via the IRQ_WAKE_THREAD return value and provides a possibility to wake it via a timer for the polling scenarios. That allows to simplify the sdio logic significantly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Chris Ball <chris@printf.net> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140215003823.772565780@linutronix.de
Diffstat (limited to 'kernel/irq/manage.c')
-rw-r--r--kernel/irq/manage.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 274ba9238fb7..54eb5c99351b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -911,6 +911,33 @@ static int irq_thread(void *data)
return 0;
}
+/**
+ * irq_wake_thread - wake the irq thread for the action identified by dev_id
+ * @irq: Interrupt line
+ * @dev_id: Device identity for which the thread should be woken
+ *
+ */
+void irq_wake_thread(unsigned int irq, void *dev_id)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irqaction *action;
+ unsigned long flags;
+
+ if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
+ return;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+ for (action = desc->action; action; action = action->next) {
+ if (action->dev_id == dev_id) {
+ if (action->thread)
+ __irq_wake_thread(desc, action);
+ break;
+ }
+ }
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL_GPL(irq_wake_thread);
+
static void irq_setup_forced_threading(struct irqaction *new)
{
if (!force_irqthreads)
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