linux-toradex.git/kernel/irq/manage.c, branch v3.0.95

genirq: Fix can_request_irq() for IRQs without an action

2013-07-22T01:14:41+00:00

commit 2779db8d37d4b542d9ca2575f5f178dbeaca6c86 upstream.

Commit 02725e7471b8 ('genirq: Use irq_get/put functions'),
inadvertently changed can_request_irq() to return 0 for IRQs that have
no action.  This causes pcibios_lookup_irq() to select only IRQs that
already have an action with IRQF_SHARED set, or to fail if there are
none.  Change can_request_irq() to return 1 for IRQs that have no
action (if the first two conditions are met).

Reported-by: Bjarni Ingi Gislason 
Tested-by: Bjarni Ingi Gislason  (against 3.2)
Signed-off-by: Ben Hutchings 
Cc: 709647@bugs.debian.org
Link: http://bugs.debian.org/709647
Link: http://lkml.kernel.org/r/1372383630.23847.40.camel@deadeye.wl.decadent.org.uk
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

genirq: Always force thread affinity

2013-01-11T17:03:38+00:00

commit 04aa530ec04f61875b99c12721162e2964e3318c upstream.

Sankara reported that the genirq core code fails to adjust the
affinity of an interrupt thread in several cases:

 1) On request/setup_irq() the call to setup_affinity() happens before
    the new action is registered, so the new thread is not notified.

 2) For secondary shared interrupts nothing notifies the new thread to
    change its affinity.

 3) Interrupts which have the IRQ_NO_BALANCE flag set are not moving
    the thread either.

Fix this by setting the thread affinity flag right on thread creation
time. This ensures that under all circumstances the thread moves to
the right place. Requires a check in irq_thread_check_affinity for an
existing affinity mask (CONFIG_CPU_MASK_OFFSTACK=y)

Reported-and-tested-by: Sankara Muthukrishnan 
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1209041738200.2754@ionos
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

random: remove rand_initialize_irq()

2012-08-15T19:04:28+00:00

commit c5857ccf293968348e5eb4ebedc68074de3dcda6 upstream.

With the new interrupt sampling system, we are no longer using the
timer_rand_state structure in the irq descriptor, so we can stop
initializing it now.

[ Merged in fixes from Sedat to find some last missing references to
  rand_initialize_irq() ]

Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Sedat Dilek 
Signed-off-by: Greg Kroah-Hartman

genirq: Fix incorrect check for forced IRQ thread handler

2012-04-02T16:27:10+00:00

commit 540b60e24f3f4781d80e47122f0c4486a03375b8 upstream.

We do not want a bitwise AND between boolean operands

Signed-off-by: Alexander Gordeev 
Cc: Oleg Nesterov 
Link: http://lkml.kernel.org/r/20120309135912.GA2114@dhcp-26-207.brq.redhat.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

genirq: Clear action->thread_mask if IRQ_ONESHOT is not set

2012-03-12T17:32:53+00:00

commit 52abb700e16a9aa4cbc03f3d7f80206cbbc80680 upstream.

Xommit ac5637611(genirq: Unmask oneshot irqs when thread was not woken)
fails to unmask when a !IRQ_ONESHOT threaded handler is handled by
handle_level_irq.

This happens because thread_mask is or'ed unconditionally in
irq_wake_thread(), but for !IRQ_ONESHOT interrupts never cleared.  So
the check for !desc->thread_active fails and keeps the interrupt
disabled.

Keep the thread_mask zero for !IRQ_ONESHOT interrupts.

Document the thread_mask magic while at it.

Reported-and-tested-by: Sven Joachim 
Reported-and-tested-by: Stefan Lippers-Hollmann 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

genirq: Handle pending irqs in irq_startup()

2012-03-01T00:34:29+00:00

commit b4bc724e82e80478cba5fe9825b62e71ddf78757 upstream.

An interrupt might be pending when irq_startup() is called, but the
startup code does not invoke the resend logic. In some cases this
prevents the device from issuing another interrupt which renders the
device non functional.

Call the resend function in irq_startup() to keep things going.

Reported-and-tested-by: Russell King 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

genirq: Fix race condition when stopping the irq thread

2011-12-09T16:52:46+00:00

commit 550acb19269d65f32e9ac4ddb26c2b2070e37f1c upstream.

In irq_wait_for_interrupt(), the should_stop member is verified before
setting the task's state to TASK_INTERRUPTIBLE and calling schedule().
In case kthread_stop sets should_stop and wakes up the process after
should_stop is checked by the irq thread but before the task's state
is changed, the irq thread might never exit:

kthread_stop                    irq_wait_for_interrupt
------------                    ----------------------

                                 ...
...                              while (!kthread_should_stop()) {
kthread->should_stop = 1;
wake_up_process(k);
wait_for_completion(&kthread->exited);
...
                                     set_current_state(TASK_INTERRUPTIBLE);

                                     ...

                                     schedule();
                                 }

Fix this by checking if the thread should stop after modifying the
task's state.

[ tglx: Simplified it a bit ]

Signed-off-by: Ido Yariv 
Link: http://lkml.kernel.org/r/1322740508-22640-1-git-send-email-ido@wizery.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

genirq: Prevent potential NULL dereference in irq_set_irq_wake()

2011-06-10T08:53:42+00:00

In kernel/irq/manage.c::irq_set_irq_wake() we call
irq_get_desc_buslock() which may return NULL, but the code
dereferences the result unconditionally.

irq_set_irq_wake() has lots of callers - I checked a few and I couldn't
find anything that guarantees that they won't call it with some input that
will cause irq_get_desc_buslock() to return NULL, so I think it's a good
thing to test and -EINVAL was the most sane error code in this situation
that I could think of.

Not all callers test the return value of irq_set_irq_wake(), but those
that do take != 0 to mean error as far as I can see, so they should be
fine. I guess those that don't test actually should, but that's a
different issue.

Signed-off-by: Jesper Juhl 
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1106092300360.17868@swampdragon.chaosbits.net
Signed-off-by: Thomas Gleixner

irq: Handle spurios irq detection for threaded irqs

2011-06-03T12:53:15+00:00

The detection of spurios interrupts is currently limited to first level
handler. In force-threaded mode we never notice if the threaded irq does
not feel responsible.
This patch catches the return value of the threaded handler and forwards
it to the spurious detector. If the primary handler returns only
IRQ_WAKE_THREAD then the spourious detector ignores it because it gets
called again from the threaded handler.

[ tglx: Report the erroneous return value early and bail out ]

Signed-off-by: Sebastian Andrzej Siewior 
Link: http://lkml.kernel.org/r/1306824972-27067-2-git-send-email-sebastian@breakpoint.cc
Signed-off-by: Thomas Gleixner

genirq: Support per-IRQ thread disabling.

2011-04-23T13:56:24+00:00

This adds support for disabling threading on a per-IRQ basis via the IRQ
status instead of the IRQ flow, which is necessary for interrupts that
don't follow the natural IRQ flow channels, such as those that are
virtually created.

The new APIs added are simply:

	irq_set_thread()
	irq_set_nothread()

which follow the rest of the IRQ status routines.

Chained handlers also have IRQ_NOTHREAD set on them automatically, making
the lack of threading explicit rather than implicit. Subsequently, the
nothread flag can be viewed through the standard genirq debugging
facilities.

[ tglx: Fixed cleanup fallout ]

Signed-off-by: Paul Mundt 
Link: http://lkml.kernel.org/r/%3C20110406210135.GF18426%40linux-sh.org%3E
Signed-off-by: Thomas Gleixner