1 files changed, 27 insertions, 1 deletions

diff --git a/drivers/media/platform/chips-media/wave5/wave5-helper.c b/drivers/media/platform/chips-media/wave5/wave5-helper.c
index f03ad9c0de22..53a0ac068c2e 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-helper.c
+++ b/drivers/media/platform/chips-media/wave5/wave5-helper.c
@@ -27,6 +27,11 @@ const char *state_to_str(enum vpu_instance_state state)
 	}
 }
 
+int wave5_kfifo_alloc(struct vpu_instance *inst)
+{
+	return kfifo_alloc(&inst->irq_status, 16 * sizeof(int), GFP_KERNEL);
+}
+
 void wave5_cleanup_instance(struct vpu_instance *inst, struct file *filp)
 {
 	int i;
@@ -49,7 +54,7 @@ void wave5_cleanup_instance(struct vpu_instance *inst, struct file *filp)
 		v4l2_fh_del(&inst->v4l2_fh, filp);
 		v4l2_fh_exit(&inst->v4l2_fh);
 	}
-	list_del_init(&inst->list);
+	kfifo_free(&inst->irq_status);
 	ida_free(&inst->dev->inst_ida, inst->id);
 	kfree(inst->codec_info);
 	kfree(inst);
@@ -61,8 +66,29 @@ int wave5_vpu_release_device(struct file *filp,
 {
 	struct vpu_instance *inst = file_to_vpu_inst(filp);
 	int ret = 0;
+	unsigned long flags;
 
 	v4l2_m2m_ctx_release(inst->v4l2_fh.m2m_ctx);
+	/*
+	 * To prevent Null reference exception, the existing irq handler were
+	 * separated to two modules.
+	 * One is to queue interrupt reason into the irq handler,
+	 * the other is irq_thread to call the wave5_vpu_dec_finish_decode
+	 * to get decoded frame.
+	 * The list of instances should be protected between all flow of the
+	 * decoding process, but to protect the list in the irq_handler, spin lock
+	 * should be used, and mutex should be used in the irq_thread because spin lock
+	 * is not able to be used because mutex is already being used
+	 * in the wave5_vpu_dec_finish_decode.
+	 * So the spin lock and mutex were used to protect the list in the release function.
+	 */
+	ret = mutex_lock_interruptible(&inst->dev->irq_lock);
+	if (ret)
+		return ret;
+	spin_lock_irqsave(&inst->dev->irq_spinlock, flags);
+	list_del_init(&inst->list);
+	spin_unlock_irqrestore(&inst->dev->irq_spinlock, flags);
+	mutex_unlock(&inst->dev->irq_lock);
 	if (inst->state != VPU_INST_STATE_NONE) {
 		u32 fail_res;