From 2610acf46b9ed528ec2cacd717bc9d354e452b73 Mon Sep 17 00:00:00 2001 From: Andreas Platschek Date: Thu, 14 Dec 2017 12:50:51 +0100 Subject: [PATCH] dmaengine: fsl-edma: disable clks on all error paths Previously enabled clks are only disabled if clk_prepare_enable() fails. However, there are other error paths were the previously enabled clocks are not disabled. To fix the problem, fsl_disable_clocks() now takes the number of clocks that shall be disabled + unprepared. For existing calls were all clocks were already successfully prepared + enabled, DMAMUX_NR is passed to disable + unprepare all clocks. In error paths were only some clocks were successfully prepared + enabled the loop counter is passed, in order to disable + unprepare all successfully prepared + enabled clocks. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Andreas Platschek Signed-off-by: Vinod Koul --- drivers/dma/fsl-edma.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c index 6775f2c74e25..c7568869284e 100644 --- a/drivers/dma/fsl-edma.c +++ b/drivers/dma/fsl-edma.c @@ -863,11 +863,11 @@ static void fsl_edma_irq_exit( } } -static void fsl_disable_clocks(struct fsl_edma_engine *fsl_edma) +static void fsl_disable_clocks(struct fsl_edma_engine *fsl_edma, int nr_clocks) { int i; - for (i = 0; i < DMAMUX_NR; i++) + for (i = 0; i < nr_clocks; i++) clk_disable_unprepare(fsl_edma->muxclk[i]); } @@ -904,25 +904,25 @@ static int fsl_edma_probe(struct platform_device *pdev) res = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i); fsl_edma->muxbase[i] = devm_ioremap_resource(&pdev->dev, res); - if (IS_ERR(fsl_edma->muxbase[i])) + if (IS_ERR(fsl_edma->muxbase[i])) { + /* on error: disable all previously enabled clks */ + fsl_disable_clocks(fsl_edma, i); return PTR_ERR(fsl_edma->muxbase[i]); + } sprintf(clkname, "dmamux%d", i); fsl_edma->muxclk[i] = devm_clk_get(&pdev->dev, clkname); if (IS_ERR(fsl_edma->muxclk[i])) { dev_err(&pdev->dev, "Missing DMAMUX block clock.\n"); + /* on error: disable all previously enabled clks */ + fsl_disable_clocks(fsl_edma, i); return PTR_ERR(fsl_edma->muxclk[i]); } ret = clk_prepare_enable(fsl_edma->muxclk[i]); - if (ret) { - /* disable only clks which were enabled on error */ - for (; i >= 0; i--) - clk_disable_unprepare(fsl_edma->muxclk[i]); - - dev_err(&pdev->dev, "DMAMUX clk block failed.\n"); - return ret; - } + if (ret) + /* on error: disable all previously enabled clks */ + fsl_disable_clocks(fsl_edma, i); } @@ -976,7 +976,7 @@ static int fsl_edma_probe(struct platform_device *pdev) if (ret) { dev_err(&pdev->dev, "Can't register Freescale eDMA engine. (%d)\n", ret); - fsl_disable_clocks(fsl_edma); + fsl_disable_clocks(fsl_edma, DMAMUX_NR); return ret; } @@ -985,7 +985,7 @@ static int fsl_edma_probe(struct platform_device *pdev) dev_err(&pdev->dev, "Can't register Freescale eDMA of_dma. (%d)\n", ret); dma_async_device_unregister(&fsl_edma->dma_dev); - fsl_disable_clocks(fsl_edma); + fsl_disable_clocks(fsl_edma, DMAMUX_NR); return ret; } @@ -1015,7 +1015,7 @@ static int fsl_edma_remove(struct platform_device *pdev) fsl_edma_cleanup_vchan(&fsl_edma->dma_dev); of_dma_controller_free(np); dma_async_device_unregister(&fsl_edma->dma_dev); - fsl_disable_clocks(fsl_edma); + fsl_disable_clocks(fsl_edma, DMAMUX_NR); return 0; } -- 2.30.2