2012-08-04 08:35:40

by Julia Lawall

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

From: Julia Lawall <[email protected]>

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 <[email protected]>

---
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;
}


2012-08-04 23:53:52

by Barry Song

[permalink] [raw]
Subject: Re: [PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions

2012/8/4 Julia Lawall <[email protected]>
>
> From: Julia Lawall <[email protected]>
>
> 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 <[email protected]>

Acked-by: Barry Song <[email protected]>

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

2012-08-22 04:14:26

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions

On Sat, 2012-08-04 at 10:35 +0200, Julia Lawall wrote:
> From: Julia Lawall <[email protected]>
>
> Fix some problems with the use of devm_ functions.
Applied, thanks


--
~Vinod

2012-08-22 05:25:36

by Barry Song

[permalink] [raw]
Subject: Re: [PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions

2012/8/22 Vinod Koul <[email protected]>:
> On Sat, 2012-08-04 at 10:35 +0200, Julia Lawall wrote:
>> From: Julia Lawall <[email protected]>
>>
>> Fix some problems with the use of devm_ functions.
> Applied, thanks

the git log "drivers/dma/sirf-dma.c: fix usage of devm functions"
should be fixed.

>
>
> --
> ~Vinod
>

-barry

2012-08-22 05:30:51

by Julia Lawall

[permalink] [raw]
Subject: Re: [PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions

On Wed, 22 Aug 2012, Barry Song wrote:

> 2012/8/22 Vinod Koul <[email protected]>:
>> On Sat, 2012-08-04 at 10:35 +0200, Julia Lawall wrote:
>>> From: Julia Lawall <[email protected]>
>>>
>>> Fix some problems with the use of devm_ functions.
>> Applied, thanks
>
> the git log "drivers/dma/sirf-dma.c: fix usage of devm functions"
> should be fixed.

What do you suggest? The patch is about problems with the use of
devm_kzalloc, devm_ioremap, and devm_request_irq.

thanks,
julia

>
>>
>>
>> --
>> ~Vinod
>>
>
> -barry
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

2012-08-22 05:42:11

by Barry Song

[permalink] [raw]
Subject: Re: [PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions

2012/8/22 Julia Lawall <[email protected]>:
> On Wed, 22 Aug 2012, Barry Song wrote:
>
>> 2012/8/22 Vinod Koul <[email protected]>:
>>>
>>> On Sat, 2012-08-04 at 10:35 +0200, Julia Lawall wrote:
>>>>
>>>> From: Julia Lawall <[email protected]>
>>>>
>>>> Fix some problems with the use of devm_ functions.
>>>
>>> Applied, thanks
>>
>>
>> the git log "drivers/dma/sirf-dma.c: fix usage of devm functions"
>> should be fixed.
>
>
> What do you suggest? The patch is about problems with the use of
> devm_kzalloc, devm_ioremap, and devm_request_irq.

i mean the prefix

dmaengine: sirf: .............

>
> thanks,
> julia

-barry

2012-08-22 06:32:37

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions

On Wed, 2012-08-22 at 13:41 +0800, Barry Song wrote:
> >>
> >>
> >> the git log "drivers/dma/sirf-dma.c: fix usage of devm functions"
> >> should be fixed.
> >
> >
> > What do you suggest? The patch is about problems with the use of
> > devm_kzalloc, devm_ioremap, and devm_request_irq.
>
> i mean the prefix
>
> dmaengine: sirf: .............
That is the usual way, it helps if you see the notation used by
subsystem by checking patches being sent to subsystem, but it is not a
really big deal, pls take care of this in future.


--
~Vinod

2012-08-22 06:38:50

by Julia Lawall

[permalink] [raw]
Subject: Re: [PATCH] drivers/dma/sirf-dma.c: fix usage of devm functions

>> dmaengine: sirf: .............
> That is the usual way, it helps if you see the notation used by
> subsystem by checking patches being sent to subsystem, but it is not a
> really big deal, pls take care of this in future.

OK.

julia