From: Phil Elwell Date: Fri, 11 Jan 2019 11:34:53 +0000 (+0000) Subject: staging: vchiq: Fix local event signalling X-Git-Tag: v5.0-rc4~19^2~3 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=a50c4c9a65779ca835746b5fd79d3d5278afbdbe;p=linux.git staging: vchiq: Fix local event signalling Prior to the recent event reworking (see Fixes), thread synchronisation was implemented using completions, the worker thread being woken with a call to complete(). The replacement uses waitqueues, which are more like condition variables in that the waiting thread is only woken if the condition is true. When the VPU signals the ARM, it first sets the event's fired flag to indicate which event is being signalled, but the places in the ARM-side code where the worker thread is being woken - remote_event_signal_local via request_poll - did not do so as it wasn't previously necessary, and since the armed flag was being cleared this lead to a deadlock. Fixes: 852b2876a8a8 ("staging: vchiq: rework remove_event handling") Signed-off-by: Phil Elwell Tested-by: Stefan Wahren Signed-off-by: Greg Kroah-Hartman --- 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 9e17ec651bde..53f5a1cb4636 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.c @@ -446,6 +446,7 @@ remote_event_wait(wait_queue_head_t *wq, struct remote_event *event) static inline void remote_event_signal_local(wait_queue_head_t *wq, struct remote_event *event) { + event->fired = 1; event->armed = 0; wake_up_all(wq); }