linux-kernel - [PATCH 5.15 227/230] dmaengine: qcom: bam

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Date:   Mon, 11 Jul 2022 11:08:03 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Stephan Gerhold <stephan@...hold.net>,
        Caleb Connolly <caleb.connolly@...aro.org>,
        Vinod Koul <vkoul@...nel.org>
Subject: [PATCH 5.15 227/230] dmaengine: qcom: bam_dma: fix runtime PM underflow

From: Caleb Connolly <caleb.connolly@...aro.org>

commit 0ac9c3dd0d6fe293cd5044cfad10bec27d171e4e upstream.

Commit dbad41e7bb5f ("dmaengine: qcom: bam_dma: check if the runtime pm enabled")
caused unbalanced pm_runtime_get/put() calls when the bam is
controlled remotely. This commit reverts it and just enables pm_runtime
in all cases, the clk_* functions already just nop when the clock is NULL.

Also clean up a bit by removing unnecessary bamclk null checks.

Suggested-by: Stephan Gerhold <stephan@...hold.net>
Fixes: dbad41e7bb5f ("dmaengine: qcom: bam_dma: check if the runtime pm enabled")
Signed-off-by: Caleb Connolly <caleb.connolly@...aro.org>
Link: https://lore.kernel.org/r/20220629140559.118537-1-caleb.connolly@linaro.org
Signed-off-by: Vinod Koul <vkoul@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/dma/qcom/bam_dma.c |   39 +++++++++++----------------------------
 1 file changed, 11 insertions(+), 28 deletions(-)

--- a/drivers/dma/qcom/bam_dma.c
+++ b/drivers/dma/qcom/bam_dma.c
@@ -515,14 +515,6 @@ static int bam_alloc_chan(struct dma_cha
 	return 0;
 }
 
-static int bam_pm_runtime_get_sync(struct device *dev)
-{
-	if (pm_runtime_enabled(dev))
-		return pm_runtime_get_sync(dev);
-
-	return 0;
-}
-
 /**
  * bam_free_chan - Frees dma resources associated with specific channel
  * @chan: specified channel
@@ -538,7 +530,7 @@ static void bam_free_chan(struct dma_cha
 	unsigned long flags;
 	int ret;
 
-	ret = bam_pm_runtime_get_sync(bdev->dev);
+	ret = pm_runtime_get_sync(bdev->dev);
 	if (ret < 0)
 		return;
 
@@ -734,7 +726,7 @@ static int bam_pause(struct dma_chan *ch
 	unsigned long flag;
 	int ret;
 
-	ret = bam_pm_runtime_get_sync(bdev->dev);
+	ret = pm_runtime_get_sync(bdev->dev);
 	if (ret < 0)
 		return ret;
 
@@ -760,7 +752,7 @@ static int bam_resume(struct dma_chan *c
 	unsigned long flag;
 	int ret;
 
-	ret = bam_pm_runtime_get_sync(bdev->dev);
+	ret = pm_runtime_get_sync(bdev->dev);
 	if (ret < 0)
 		return ret;
 
@@ -869,7 +861,7 @@ static irqreturn_t bam_dma_irq(int irq,
 	if (srcs & P_IRQ)
 		tasklet_schedule(&bdev->task);
 
-	ret = bam_pm_runtime_get_sync(bdev->dev);
+	ret = pm_runtime_get_sync(bdev->dev);
 	if (ret < 0)
 		return IRQ_NONE;
 
@@ -987,7 +979,7 @@ static void bam_start_dma(struct bam_cha
 	if (!vd)
 		return;
 
-	ret = bam_pm_runtime_get_sync(bdev->dev);
+	ret = pm_runtime_get_sync(bdev->dev);
 	if (ret < 0)
 		return;
 
@@ -1350,11 +1342,6 @@ static int bam_dma_probe(struct platform
 	if (ret)
 		goto err_unregister_dma;
 
-	if (!bdev->bamclk) {
-		pm_runtime_disable(&pdev->dev);
-		return 0;
-	}
-
 	pm_runtime_irq_safe(&pdev->dev);
 	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
 	pm_runtime_use_autosuspend(&pdev->dev);
@@ -1438,10 +1425,8 @@ static int __maybe_unused bam_dma_suspen
 {
 	struct bam_device *bdev = dev_get_drvdata(dev);
 
-	if (bdev->bamclk) {
-		pm_runtime_force_suspend(dev);
-		clk_unprepare(bdev->bamclk);
-	}
+	pm_runtime_force_suspend(dev);
+	clk_unprepare(bdev->bamclk);
 
 	return 0;
 }
@@ -1451,13 +1436,11 @@ static int __maybe_unused bam_dma_resume
 	struct bam_device *bdev = dev_get_drvdata(dev);
 	int ret;
 
-	if (bdev->bamclk) {
-		ret = clk_prepare(bdev->bamclk);
-		if (ret)
-			return ret;
+	ret = clk_prepare(bdev->bamclk);
+	if (ret)
+		return ret;
 
-		pm_runtime_force_resume(dev);
-	}
+	pm_runtime_force_resume(dev);
 
 	return 0;
 }