linux-toradex.git/kernel/irq/handle.c, branch v4.3

genirq: Fix handle_bad_irq kerneldoc comment

2015-10-09T15:17:30+00:00

A recent cleanup removed the 'irq' parameter from many functions, but
left the documentation for this in place for at least one function.

This removes it.

Fixes: bd0b9ac405e1 ("genirq: Remove irq argument from irq flow handlers")
Reported-by: kbuild test robot 
Signed-off-by: Arnd Bergmann 
Cc: Grygorii Strashko 
Cc: Tony Lindgren 
Cc: Linus Walleij 
Cc: kbuild-all@01.org
Cc: Austin Schuh 
Cc: Santosh Shilimkar 
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/5400000.cD19rmgWjV@wuerfel
Signed-off-by: Thomas Gleixner

genirq: Export handle_bad_irq

2015-10-09T15:17:30+00:00

A cleanup of the omap gpio driver introduced a use of the
handle_bad_irq() function in a device driver that can be
a loadable module.

This broke the ARM allmodconfig build:

ERROR: "handle_bad_irq" [drivers/gpio/gpio-omap.ko] undefined!

This patch exports the handle_bad_irq symbol in order to
allow the use in modules.

Signed-off-by: Arnd Bergmann 
Cc: Grygorii Strashko 
Cc: Santosh Shilimkar 
Cc: Linus Walleij 
Cc: Austin Schuh 
Cc: Tony Lindgren 
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/5847725.4IBopItaOr@wuerfel
Signed-off-by: Thomas Gleixner

genirq: Remove irq argument from irq flow handlers

2015-09-16T13:47:51+00:00

Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!

Signed-off-by: Thomas Gleixner 
Cc: Julia Lawall 
Cc: Jiang Liu

genirq: Remove the irq argument from note_interrupt()

2015-07-11T21:14:25+00:00

Only required for the slow path. Retrieve it from irq descriptor if
necessary.

[ tglx: Split out from combo patch. Left [try_]misrouted_irq()
  	untouched as there is no win in the slow path ]

Signed-off-by: Jiang Liu 
Cc: Konrad Rzeszutek Wilk 
Cc: Tony Luck 
Cc: Bjorn Helgaas 
Cc: Benjamin Herrenschmidt 
Cc: Randy Dunlap 
Cc: Yinghai Lu 
Cc: Borislav Petkov 
Cc: Jason Cooper 
Cc: Kevin Cernekee 
Cc: Arnd Bergmann 
Link: http://lkml.kernel.org/r/1433391238-19471-19-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner

genirq: Remove the parameter 'irq' of kstat_incr_irqs_this_cpu()

2015-07-11T21:14:24+00:00

The first parameter 'irq' is never used by
kstat_incr_irqs_this_cpu(). Remove it.

Signed-off-by: Jiang Liu 
Cc: Konrad Rzeszutek Wilk 
Cc: Tony Luck 
Cc: Bjorn Helgaas 
Cc: Benjamin Herrenschmidt 
Cc: Randy Dunlap 
Cc: Yinghai Lu 
Cc: Borislav Petkov 
Link: http://lkml.kernel.org/r/1433391238-19471-16-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner

genirq: Export symbol no_action()

2014-03-22T10:33:09+00:00

This will allow to use the dummy IRQ handler no_action() from drivers
compiled as module. Drivers which use ARM FIQ interrupts can use this
to request the interrupt via the normal request_irq() mechanism w/o
having to copy the dummy handler to their own code.

Signed-off-by: Alexander Shiyan 
Link: http://lkml.kernel.org/r/1395476431-16070-1-git-send-email-shc_work@mail.ru
Signed-off-by: Thomas Gleixner

genirq: Provide irq_wake_thread()

2014-02-19T16:22:44+00:00

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 
Cc: Russell King 
Cc: Chris Ball 
Acked-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20140215003823.772565780@linutronix.de

random: make 'add_interrupt_randomness()' do something sane

2012-07-15T00:17:28+00:00

We've been moving away from add_interrupt_randomness() for various
reasons: it's too expensive to do on every interrupt, and flooding the
CPU with interrupts could theoretically cause bogus floods of entropy
from a somewhat externally controllable source.

This solves both problems by limiting the actual randomness addition
to just once a second or after 64 interrupts, whicever comes first.
During that time, the interrupt cycle data is buffered up in a per-cpu
pool.  Also, we make sure the the nonblocking pool used by urandom is
initialized before we start feeding the normal input pool.  This
assures that /dev/urandom is returning unpredictable data as soon as
possible.

(Based on an original patch by Linus, but significantly modified by
tytso.)

Tested-by: Eric Wustrow 
Reported-by: Eric Wustrow 
Reported-by: Nadia Heninger 
Reported-by: Zakir Durumeric 
Reported-by: J. Alex Halderman .
Signed-off-by: Linus Torvalds 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@vger.kernel.org

genirq: Minor readablity improvement in irq_wake_thread()

2012-03-29T09:31:52+00:00

exit_irq_thread() clears IRQTF_RUNTHREAD flag and drops the thread's bit in
desc->threads_oneshot then. The bit must not be set again in between and it
does not, since irq_wake_thread() sees PF_EXITING flag first and returns.

Due to above the order or checking PF_EXITING and IRQTF_RUNTHREAD flags in
irq_wake_thread() is important. This change just makes it more visible in the
source code.

Signed-off-by: Alexander Gordeev 
Link: http://lkml.kernel.org/r/20120321162212.GO24806@dhcp-26-207.brq.redhat.com
Signed-off-by: Thomas Gleixner

genirq: Flush the irq thread on synchronization

2012-03-14T10:56:20+00:00

The current implementation does not always flush the threaded handler
when disabling the irq. In case the irq handler was called, but the
threaded handler hasn't started running yet, the interrupt will be
flagged as pending, and the handler will not run. This implementation
has some issues:

First, if the interrupt is a wake source and flagged as pending, the
system will not be able to suspend.

Second, when quickly disabling and re-enabling the irq, the threaded
handler might continue to run after the irq is re-enabled without the
irq handler being called first. This might be an unexpected behavior.

In addition, it might be counter-intuitive that the threaded handler
will not be called even though the irq handler was called and returned
IRQ_WAKE_THREAD.

Fix this by always waiting for the threaded handler to complete in
synchronize_irq().

[ tglx: Massaged comments, added WARN_ONs and the missing
  	IRQTF_RUNTHREAD check in exit_irq_thread() ]

Signed-off-by: Ido Yariv 
Link: http://lkml.kernel.org/r/1322843052-7166-1-git-send-email-ido@wizery.com
Signed-off-by: Thomas Gleixner