linux/kernel/irq
Thomas Gleixner b25c340c19 genirq: Add oneshot support
For threaded interrupt handlers we expect the hard interrupt handler
part to mask the interrupt on the originating device. The interrupt
line itself is reenabled after the hard interrupt handler has
executed.

This requires access to the originating device from hard interrupt
context which is not always possible. There are devices which can only
be accessed via a bus (i2c, spi, ...). The bus access requires thread
context. For such devices we need to keep the interrupt line masked
until the threaded handler has executed.

Add a new flag IRQF_ONESHOT which allows drivers to request that the
interrupt is not unmasked after the hard interrupt context handler has
been executed and the thread has been woken. The interrupt line is
unmasked after the thread handler function has been executed.

Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to
avoid complex accounting mechanisms.

For oneshot interrupts the primary handler simply returns
IRQ_WAKE_THREAD and does nothing else. A generic implementation
irq_default_primary_handler() is provided to avoid useless copies all
over the place. It is automatically installed when
request_threaded_irq() is called with handler=NULL and
thread_fn!=NULL.

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>
2009-08-17 10:54:05 +02:00
..
Makefile x86/irq: use move_irq_desc() in create_irq_nr() 2009-05-01 19:01:12 +02:00
autoprobe.c async: Asynchronous function calls to speed up kernel boot 2009-01-07 08:45:46 -08:00
chip.c genirq: Add oneshot support 2009-08-17 10:54:05 +02:00
devres.c genirq: add support for threaded interrupts to devres 2009-03-24 12:15:23 +01:00
handle.c irq: slab alloc for default irq_affinity 2009-06-12 13:50:23 +03:00
internals.h genirq: Delegate irq affinity setting to the irq thread 2009-07-21 14:35:07 +02:00
manage.c genirq: Add oneshot support 2009-08-17 10:54:05 +02:00
migration.c genirq: Delegate irq affinity setting to the irq thread 2009-07-21 14:35:07 +02:00
numa_migrate.c x86/irq: Fix move_irq_desc() for nodes without ram 2009-08-08 17:06:03 +02:00
pm.c PM: Introduce functions for suspending and resuming device interrupts 2009-03-30 21:46:54 +02:00
proc.c cpumask: update irq_desc to use cpumask_var_t 2009-01-11 19:12:46 +01:00
resend.c generic: sparse irqs: use irq_desc() together with dyn_array, instead of irq_desc[] 2008-10-16 16:52:29 +02:00
spurious.c irq: provide debug_poll_all_shared_irqs() method under CONFIG_DEBUG_SHIRQ 2009-01-16 17:46:49 +01:00