[PATCH] mailbox: remove runtime GCE clk control

From: jason-jh.lin <hidden>
Date: 2021-12-14 10:31:31
Also in: linux-arm-kernel
Subsystem: mailbox api, the rest · Maintainers: Jassi Brar, Linus Torvalds

1. GCE is a frequently used module, so runtime controlling
GCE clk may not saving too much power.

2. mt8195 sharing the same event table for 2 GCE core.
Runtime controlling 2 GCE clk will cause display HW register
configured in worng stream done event issue below:
  GCE should config HW in every vblanking duration.
  The stream done event is the start signal of vblanking.

  If stream done event is sent between GCE clk_disable
  and clk_enable. After GCE clk_enable the stream done event
  may not appear immediately and have about 3us delay.

  Normal case:
  clk_disable -> get EventA -> clk_enable -> clear EventA
  -> wait EventB -> get EventB -> config HW

  Abnormal case:
  clk_disable -> get EventA -> clk_enable -> EventA delay appear
  -> clear EventA fail -> wait EventB but get EventA -> config HW

So just remove the runtime GCE clock contorl.

Signed-off-by: jason-jh.lin <redacted>
---
 drivers/mailbox/mtk-cmdq-mailbox.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index 342b91f16e65..1faf35e8aff0 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c

@@ -127,13 +127,11 @@ static void cmdq_init(struct cmdq *cmdq)
 {
 	int i;
 
-	WARN_ON(clk_bulk_enable(cmdq->gce_num, cmdq->clocks));
 	if (cmdq->control_by_sw)
 		writel(0x7, cmdq->base + GCE_GCTL_VALUE);
 	writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
 	for (i = 0; i <= CMDQ_MAX_EVENT; i++)
 		writel(i, cmdq->base + CMDQ_SYNC_TOKEN_UPDATE);
-	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
 }
 
 static int cmdq_thread_reset(struct cmdq *cmdq, struct cmdq_thread *thread)

@@ -269,10 +267,8 @@ static void cmdq_thread_irq_handler(struct cmdq *cmdq,
 			break;
 	}
 
-	if (list_empty(&thread->task_busy_list)) {
+	if (list_empty(&thread->task_busy_list))
 		cmdq_thread_disable(cmdq, thread);
-		clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
-	}
 }
 
 static irqreturn_t cmdq_irq_handler(int irq, void *dev)

@@ -316,7 +312,7 @@ static int cmdq_suspend(struct device *dev)
 	if (task_running)
 		dev_warn(dev, "exist running task(s) in suspend\n");
 
-	clk_bulk_unprepare(cmdq->gce_num, cmdq->clocks);
+	clk_bulk_disable_unprepare(cmdq->gce_num, cmdq->clocks);
 
 	return 0;
 }

@@ -325,7 +321,7 @@ static int cmdq_resume(struct device *dev)
 {
 	struct cmdq *cmdq = dev_get_drvdata(dev);
 
-	WARN_ON(clk_bulk_prepare(cmdq->gce_num, cmdq->clocks));
+	WARN_ON(clk_bulk_prepare_enable(cmdq->gce_num, cmdq->clocks));
 	cmdq->suspended = false;
 	return 0;
 }

@@ -334,7 +330,7 @@ static int cmdq_remove(struct platform_device *pdev)
 {
 	struct cmdq *cmdq = platform_get_drvdata(pdev);
 
-	clk_bulk_unprepare(cmdq->gce_num, cmdq->clocks);
+	clk_bulk_disable_unprepare(cmdq->gce_num, cmdq->clocks);
 	return 0;
 }

@@ -360,8 +356,6 @@ static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
 	task->pkt = pkt;
 
 	if (list_empty(&thread->task_busy_list)) {
-		WARN_ON(clk_bulk_enable(cmdq->gce_num, cmdq->clocks));
-
 		/*
 		 * The thread reset will clear thread related register to 0,
 		 * including pc, end, priority, irq, suspend and enable. Thus

@@ -433,7 +427,6 @@ static void cmdq_mbox_shutdown(struct mbox_chan *chan)
 	}
 
 	cmdq_thread_disable(cmdq, thread);
-	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
 
 done:
 	/*

@@ -479,7 +472,6 @@ static int cmdq_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
 
 	cmdq_thread_resume(thread);
 	cmdq_thread_disable(cmdq, thread);
-	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
 
 out:
 	spin_unlock_irqrestore(&thread->chan->lock, flags);

@@ -621,7 +613,7 @@ static int cmdq_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, cmdq);
 
-	WARN_ON(clk_bulk_prepare(cmdq->gce_num, cmdq->clocks));
+	WARN_ON(clk_bulk_prepare_enable(cmdq->gce_num, cmdq->clocks));
 
 	cmdq_init(cmdq);

-- 
2.18.0


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