From 615eee2c45c8448feca0be4e3ad7723916b90744 Mon Sep 17 00:00:00 2001 From: Etienne Carriere Date: Wed, 29 Jan 2020 16:36:23 +0100 Subject: [PATCH] dmaengine: stm32-dma: driver defers probe for reset Change STM32 DMA driver to defer its probe operation when reset controller is expected but has not been probed yet when DMA device is probed. Changes error traces when failing to get a system resource so that it is not printed on failure with deferred probing. Signed-off-by: Etienne Carriere Signed-off-by: Amelie Delaunay Link: https://lore.kernel.org/r/20200129153628.29329-4-amelie.delaunay@st.com Signed-off-by: Vinod Koul --- drivers/dma/stm32-dma.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index e31414796ec4..c8bbe08b8e32 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -1296,8 +1296,10 @@ static int stm32_dma_probe(struct platform_device *pdev) dmadev->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(dmadev->clk)) { - dev_err(&pdev->dev, "Error: Missing controller clock\n"); - return PTR_ERR(dmadev->clk); + ret = PTR_ERR(dmadev->clk); + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, "Can't get clock\n"); + return ret; } ret = clk_prepare_enable(dmadev->clk); @@ -1310,7 +1312,11 @@ static int stm32_dma_probe(struct platform_device *pdev) "st,mem2mem"); rst = devm_reset_control_get(&pdev->dev, NULL); - if (!IS_ERR(rst)) { + if (IS_ERR(rst)) { + ret = PTR_ERR(rst); + if (ret == -EPROBE_DEFER) + goto clk_free; + } else { reset_control_assert(rst); udelay(2); reset_control_deassert(rst); @@ -1470,10 +1476,11 @@ static struct platform_driver stm32_dma_driver = { .of_match_table = stm32_dma_of_match, .pm = &stm32_dma_pm_ops, }, + .probe = stm32_dma_probe, }; static int __init stm32_dma_init(void) { - return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe); + return platform_driver_register(&stm32_dma_driver); } subsys_initcall(stm32_dma_init);