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Subject[PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions
Date
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>

---
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;
}



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