mirror of
https://github.com/LibreELEC/LibreELEC.tv.git
synced 2025-07-24 11:16:51 +00:00
[Wetek.Play/amlkernel] - fix race condition in ge2d_wq.
1. thread 1 is here https://github.com/codesnake/linux-amlogic/blob/master/drivers/amlogic/display/ge2d/ge2d_wq.c#L147 2. thread 2 is here https://github.com/codesnake/linux-amlogic/blob/master/drivers/amlogic/display/ge2d/ge2d_wq.c#L855 3. thread 2 is running and enters the if condition because state is GE2D_STATE_RUNNING 4. thread 2 gets interrupted by thread 1 thread 1 jumps over the if and sets GE2D_STATE_IDLE and is done 5. back to thread 2 which now sets state GE2D_STATE_REMOVING_WQ and calls wait_for_completion 6. thread2 will never return because thread 1 is done already and won't signal the event destroy_ge2d_work_queue is called from https://github.com/codesnake/linux-amlogic/blob/master/drivers/amlogic/amports/amvideocap.c#L320 in my use case and will block there forever - and basically blocks down to the read in the userspace which tries to read the current captured frame
This commit is contained in:
parent
14592b4cd3
commit
d12146f9e4
@ -0,0 +1,53 @@
|
||||
--- a/include/linux/amlogic/ge2d/ge2d_wq.h 2015-01-14 00:46:24.916408987 +0100
|
||||
+++ b/include/linux/amlogic/ge2d/ge2d_wq.h 2015-01-14 00:45:24.233715480 +0100
|
||||
@@ -81,6 +81,7 @@
|
||||
ge2d_event_t event ;
|
||||
int irq_num;
|
||||
int ge2d_state;
|
||||
+ spinlock_t state_lock; //for sync access to ge2d_state
|
||||
int process_queue_state;
|
||||
}ge2d_manager_t ;
|
||||
|
||||
--- a/drivers/amlogic/display/ge2d/ge2d_wq.c 2015-01-14 00:59:18.775744127 +0100
|
||||
+++ b/drivers/amlogic/display/ge2d/ge2d_wq.c 2015-01-14 00:58:59.440160948 +0100
|
||||
@@ -144,9 +144,11 @@
|
||||
}while(pos!=head);
|
||||
ge2d_manager.last_wq=wq;
|
||||
exit:
|
||||
+ spin_lock(&ge2d_manager.state_lock);
|
||||
if(ge2d_manager.ge2d_state==GE2D_STATE_REMOVING_WQ)
|
||||
- complete(&ge2d_manager.event.process_complete);
|
||||
+ complete(&ge2d_manager.event.process_complete);
|
||||
ge2d_manager.ge2d_state=GE2D_STATE_IDLE;
|
||||
+ spin_unlock(&ge2d_manager.state_lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
@@ -854,8 +856,17 @@
|
||||
spin_unlock(&ge2d_manager.event.sem_lock);
|
||||
if((ge2d_manager.current_wq==ge2d_work_queue)&&(ge2d_manager.ge2d_state== GE2D_STATE_RUNNING))
|
||||
{
|
||||
- ge2d_manager.ge2d_state=GE2D_STATE_REMOVING_WQ;
|
||||
- wait_for_completion(&ge2d_manager.event.process_complete);
|
||||
+ // check again with lock
|
||||
+ int wasRunning = 0;
|
||||
+ spin_lock(&ge2d_manager.state_lock);
|
||||
+ if (ge2d_manager.ge2d_state== GE2D_STATE_RUNNING)
|
||||
+ {
|
||||
+ ge2d_manager.ge2d_state=GE2D_STATE_REMOVING_WQ;
|
||||
+ wasRunning = 1;
|
||||
+ }
|
||||
+ spin_unlock(&ge2d_manager.state_lock);
|
||||
+ if (wasRunning)
|
||||
+ wait_for_completion(&ge2d_manager.event.process_complete);
|
||||
ge2d_manager.last_wq=NULL; //condition so complex ,simplify it .
|
||||
}//else we can delete it safely.
|
||||
|
||||
@@ -902,6 +913,7 @@
|
||||
//prepare bottom half
|
||||
|
||||
spin_lock_init(&ge2d_manager.event.sem_lock);
|
||||
+ spin_lock_init(&ge2d_manager.state_lock);
|
||||
sema_init (&ge2d_manager.event.cmd_in_sem,1);
|
||||
init_waitqueue_head (&ge2d_manager.event.cmd_complete);
|
||||
init_completion(&ge2d_manager.event.process_complete);
|
Loading…
x
Reference in New Issue
Block a user