The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 0ac9c3dd0d6fe293cd5044cfad10bec27d171e4e Mon Sep 17 00:00:00 2001 From: Caleb Connolly caleb.connolly@linaro.org Date: Wed, 29 Jun 2022 15:06:00 +0100 Subject: [PATCH] dmaengine: qcom: bam_dma: fix runtime PM underflow

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

diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index 87f6ca1541cf..2ff787df513e 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -558,14 +558,6 @@ static int bam_alloc_chan(struct dma_chan *chan) 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 @@ -581,7 +573,7 @@ static void bam_free_chan(struct dma_chan *chan) unsigned long flags; int ret;

- ret = bam_pm_runtime_get_sync(bdev->dev); + ret = pm_runtime_get_sync(bdev->dev); if (ret < 0) return;

@@ -784,7 +776,7 @@ static int bam_pause(struct dma_chan *chan) 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;

@@ -810,7 +802,7 @@ static int bam_resume(struct dma_chan *chan) 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;

@@ -919,7 +911,7 @@ static irqreturn_t bam_dma_irq(int irq, void *data) 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;

@@ -1037,7 +1029,7 @@ static void bam_start_dma(struct bam_chan *bchan) if (!vd) return;

- ret = bam_pm_runtime_get_sync(bdev->dev); + ret = pm_runtime_get_sync(bdev->dev); if (ret < 0) return;

@@ -1374,11 +1366,6 @@ static int bam_dma_probe(struct platform_device *pdev) 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); @@ -1462,10 +1449,8 @@ static int __maybe_unused bam_dma_suspend(struct device *dev) { 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; } @@ -1475,13 +1460,11 @@ static int __maybe_unused bam_dma_resume(struct device *dev) 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; }