summaryrefslogtreecommitdiff
path: root/include/linux/irq.h
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2009-08-13 15:21:38 +0400
committerThomas Gleixner <tglx@linutronix.de>2009-08-17 12:54:05 +0400
commit399b5da29b9f851eb7b96e2882097127f003e87c (patch)
tree0264a7ae22988e8a298407c611b5b639c9315ff7 /include/linux/irq.h
parent70aedd24d20e75198f5a0b11750faabbb56924e2 (diff)
downloadlinux-399b5da29b9f851eb7b96e2882097127f003e87c.tar.xz
genirq: Support nested threaded irq handling
Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
Diffstat (limited to 'include/linux/irq.h')
-rw-r--r--include/linux/irq.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index ce8171bc6fac..8778ee993937 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -70,6 +70,7 @@ typedef void (*irq_flow_handler_t)(unsigned int irq,
#define IRQ_AFFINITY_SET 0x02000000 /* IRQ affinity was set from userspace*/
#define IRQ_SUSPENDED 0x04000000 /* IRQ has gone through suspend sequence */
#define IRQ_ONESHOT 0x08000000 /* IRQ is not unmasked after hardirq */
+#define IRQ_NESTED_THREAD 0x10000000 /* IRQ is nested into another, no own handler thread */
#ifdef CONFIG_IRQ_PER_CPU
# define CHECK_IRQ_PER_CPU(var) ((var) & IRQ_PER_CPU)
@@ -386,6 +387,8 @@ set_irq_chained_handler(unsigned int irq,
__set_irq_handler(irq, handle, 1, NULL);
}
+extern void set_irq_nested_thread(unsigned int irq, int nest);
+
extern void set_irq_noprobe(unsigned int irq);
extern void set_irq_probe(unsigned int irq);