Messages in this thread | | | Date | Fri, 21 Aug 2020 19:01:57 +0200 | From | Paul Cercueil <> | Subject | Re: [PATCH v2] drivers/dma/dma-jz4780: Fix race condition between probe and irq handler |
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Le ven. 21 août 2020 à 9:14, madhuparnabhowmik10@gmail.com a écrit : > From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> > > In probe, IRQ is requested before zchan->id is initialized which can > be > read in the irq handler. Hence, shift request irq after other > initializations > complete. > > Found by Linux Driver Verification project (linuxtesting.org). > > Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Thanks for the patch.
Cheers, -Paul
> > --- > Changes since v1: > Keep enable clock before request IRQ. > --- > drivers/dma/dma-jz4780.c | 38 +++++++++++++++++++------------------- > 1 file changed, 19 insertions(+), 19 deletions(-) > > diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c > index 448f663da89c..8beed91428bd 100644 > --- a/drivers/dma/dma-jz4780.c > +++ b/drivers/dma/dma-jz4780.c > @@ -879,24 +879,11 @@ static int jz4780_dma_probe(struct > platform_device *pdev) > return -EINVAL; > } > > - ret = platform_get_irq(pdev, 0); > - if (ret < 0) > - return ret; > - > - jzdma->irq = ret; > - > - ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, > dev_name(dev), > - jzdma); > - if (ret) { > - dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq); > - return ret; > - } > - > jzdma->clk = devm_clk_get(dev, NULL); > if (IS_ERR(jzdma->clk)) { > dev_err(dev, "failed to get clock\n"); > ret = PTR_ERR(jzdma->clk); > - goto err_free_irq; > + return ret; > } > > clk_prepare_enable(jzdma->clk); > @@ -949,10 +936,23 @@ static int jz4780_dma_probe(struct > platform_device *pdev) > jzchan->vchan.desc_free = jz4780_dma_desc_free; > } > > + ret = platform_get_irq(pdev, 0); > + if (ret < 0) > + goto err_disable_clk; > + > + jzdma->irq = ret; > + > + ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, > dev_name(dev), > + jzdma); > + if (ret) { > + dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq); > + goto err_disable_clk; > + } > + > ret = dmaenginem_async_device_register(dd); > if (ret) { > dev_err(dev, "failed to register device\n"); > - goto err_disable_clk; > + goto err_free_irq; > } > > /* Register with OF DMA helpers. */ > @@ -960,17 +960,17 @@ static int jz4780_dma_probe(struct > platform_device *pdev) > jzdma); > if (ret) { > dev_err(dev, "failed to register OF DMA controller\n"); > - goto err_disable_clk; > + goto err_free_irq; > } > > dev_info(dev, "JZ4780 DMA controller initialised\n"); > return 0; > > -err_disable_clk: > - clk_disable_unprepare(jzdma->clk); > - > err_free_irq: > free_irq(jzdma->irq, jzdma); > + > +err_disable_clk: > + clk_disable_unprepare(jzdma->clk); > return ret; > } > > -- > 2.17.1 >
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