[PATCH 5.15 227/230] dmaengine: qcom: bam_dma: fix runtime PM underflow

Greg Kroah-Hartman
2022-07-11T10:05:06Z

From: Caleb Connolly <caleb.connolly@linaro.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@gerhold.net>
Fixes: dbad41e7bb5f ("dmaengine: qcom: bam_dma: check if the runtime pm enabled")
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
Link: https://lore.kernel.org/r/20220629140559.118537-1-caleb.connolly@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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;
}