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SubjectRe: [PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions
2012/8/4 Julia Lawall <Julia.Lawall@lip6.fr>
>
> From: Julia Lawall <Julia.Lawall@lip6.fr>
>
> Fix some problems with the use of devm_ functions.
>
> devm_kzalloc: devm_kfree is not needed
>
> devm_ioremap: iounmap should not be used, no free is needed
>
> devm_request_irq: the devm_free_irq is followed by irq_dispose_mapping. I
> don't know if it is safe to move the freeing of the irq in this case, so I
> have just un-devm'd this function, since the implicit freeing is never
> taken advantage of.
>
> In the original code failure of of_address_to_resource jumped to free_mem,
> but should have jumped to irq_dispose, since irq_of_parse_and_map has
> completed at this point.
>
> In the original code unmap_mem was after irq_dispose, but it should have
> been before, again since irq_of_parse_and_map has completed at this point.
>
> One of these problems was found using the following semantic match:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression x;
> @@
>
> *x = devm_ioremap(...)
> ...
> iounmap(x);
> // </smpl>
>
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

Acked-by: Barry Song <Baohua.Song@csr.com>

thanks!

>
> ---
> Not compiled. Does free_irq actually have to be called before
> irq_dispose_mapping?
>
> drivers/dma/sirf-dma.c | 23 +++++++----------------
> 1 file changed, 7 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/dma/sirf-dma.c b/drivers/dma/sirf-dma.c
> index 434ad31..1af9e48 100644
> --- a/drivers/dma/sirf-dma.c
> +++ b/drivers/dma/sirf-dma.c
> @@ -570,21 +570,19 @@ static int __devinit sirfsoc_dma_probe(struct
> platform_device *op)
>
> if (of_property_read_u32(dn, "cell-index", &id)) {
> dev_err(dev, "Fail to get DMAC index\n");
> - ret = -ENODEV;
> - goto free_mem;
> + return -ENODEV;
> }
>
> sdma->irq = irq_of_parse_and_map(dn, 0);
> if (sdma->irq == NO_IRQ) {
> dev_err(dev, "Error mapping IRQ!\n");
> - ret = -EINVAL;
> - goto free_mem;
> + return -EINVAL;
> }
>
> ret = of_address_to_resource(dn, 0, &res);
> if (ret) {
> dev_err(dev, "Error parsing memory region!\n");
> - goto free_mem;
> + goto irq_dispose;
> }
>
> regs_start = res.start;
> @@ -597,12 +595,11 @@ static int __devinit sirfsoc_dma_probe(struct
> platform_device *op)
> goto irq_dispose;
> }
>
> - ret = devm_request_irq(dev, sdma->irq, &sirfsoc_dma_irq, 0,
> DRV_NAME,
> - sdma);
> + ret = request_irq(sdma->irq, &sirfsoc_dma_irq, 0, DRV_NAME, sdma);
> if (ret) {
> dev_err(dev, "Error requesting IRQ!\n");
> ret = -EINVAL;
> - goto unmap_mem;
> + goto irq_dispose;
> }
>
> dma = &sdma->dma;
> @@ -652,13 +649,9 @@ static int __devinit sirfsoc_dma_probe(struct
> platform_device *op)
> return 0;
>
> free_irq:
> - devm_free_irq(dev, sdma->irq, sdma);
> + free_irq(sdma->irq, sdma);
> irq_dispose:
> irq_dispose_mapping(sdma->irq);
> -unmap_mem:
> - iounmap(sdma->base);
> -free_mem:
> - devm_kfree(dev, sdma);
> return ret;
> }
>
> @@ -668,10 +661,8 @@ static int __devexit sirfsoc_dma_remove(struct
> platform_device *op)
> struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
>
> dma_async_device_unregister(&sdma->dma);
> - devm_free_irq(dev, sdma->irq, sdma);
> + free_irq(sdma->irq, sdma);
> irq_dispose_mapping(sdma->irq);
> - iounmap(sdma->base);
> - devm_kfree(dev, sdma);
> return 0;
> }

-barry


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