staging: vchiq: make wait events interruptible

commit 77cf3f5dcf35c8f547f075213dbc15146d44cc76 upstream.

The killable version of wait_event() is meant to be used on situations
where it should not fail at all costs, but still have the convenience of
being able to kill it if really necessary. Wait events in VCHIQ doesn't
fit this criteria, as it's mainly used as an interface to V4L2 and ALSA
devices.

Fixes: 852b2876a8a8 ("staging: vchiq: rework remove_event handling")
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
index bc5661dde987c82a8c982f629d130d10d841b11b..0958d86aebe6c6fa96d8367271ced24031c6af04 100644 (file)
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -425,13 +425,21 @@ remote_event_create(wait_queue_head_t *wq, struct remote_event *event)
        init_waitqueue_head(wq);
 }
 
+/*
+ * All the event waiting routines in VCHIQ used a custom semaphore
+ * implementation that filtered most signals. This achieved a behaviour similar
+ * to the "killable" family of functions. While cleaning up this code all the
+ * routines where switched to the "interruptible" family of functions, as the
+ * former was deemed unjustified and the use "killable" set all VCHIQ's
+ * threads in D state.
+ */
 static inline int
 remote_event_wait(wait_queue_head_t *wq, struct remote_event *event)
 {
        if (!event->fired) {
                event->armed = 1;
                dsb(sy);
-               if (wait_event_killable(*wq, event->fired)) {
+               if (wait_event_interruptible(*wq, event->fired)) {
                        event->armed = 0;
                        return 0;
                }