[PATCH v7 4/4] mailbox: mediatek: cmdq: clear task in channel before shutdown

[Dennis YC Hsieh]

Do success callback in channel when shutdown. For those task not finish,
callback with error code thus client has chance to cleanup or reset.

Signed-off-by: Dennis YC Hsieh <dennis-yc.hsieh at mediatek.com>
Reviewed-by: CK Hu <ck.hu at mediatek.com>
---
 drivers/mailbox/mtk-cmdq-mailbox.c |   38 ++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index 9994ac9426d6..b56d340c8982 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -387,6 +387,12 @@ static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
 
 	if (list_empty(&thread->task_busy_list)) {
 		WARN_ON(clk_enable(cmdq->clock) < 0);
+		/*
+		 * The thread reset will clear thread related register to 0,
+		 * including pc, end, priority, irq, suspend and enable. Thus
+		 * set CMDQ_THR_ENABLED to CMDQ_THR_ENABLE_TASK will enable
+		 * thread and make it running.
+		 */
 		WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);
 
 		writel(task->pa_base >> cmdq->shift_pa,
@@ -450,6 +456,38 @@ static int cmdq_mbox_startup(struct mbox_chan *chan)
 
 static void cmdq_mbox_shutdown(struct mbox_chan *chan)
 {
+	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
+	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
+	struct cmdq_task *task, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&thread->chan->lock, flags);
+	if (list_empty(&thread->task_busy_list))
+		goto done;
+
+	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
+
+	/* make sure executed tasks have success callback */
+	cmdq_thread_irq_handler(cmdq, thread);
+	if (list_empty(&thread->task_busy_list))
+		goto done;
+
+	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
+				 list_entry) {
+		cmdq_task_exec_done(task, CMDQ_CB_ERROR);
+		kfree(task);
+	}
+
+	cmdq_thread_disable(cmdq, thread);
+	clk_disable(cmdq->clock);
+done:
+	/*
+	 * The thread->task_busy_list empty means thread already disable. The
+	 * cmdq_mbox_send_data() always reset thread which clear disable and
+	 * suspend statue when first pkt send to channel, so there is no need
+	 * to do any operation here, only unlock and leave.
+	 */
+	spin_unlock_irqrestore(&thread->chan->lock, flags);
 }
 
 static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
-- 
1.7.9.5