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SubjectRe: [PATCH 5/5] drivers/i2c/busses/i2c-nuc900.c: Convert release_resource to release_region/release_mem_region
Date
On Sunday 13 February 2011 13:12:12 Julia Lawall wrote:
> Request_region should be used with release_region, not release_resource.
>
> The result of request_mem_region is no longer stored. Instead the field
> ioarea is used to store a pointer to the resource structure that contains
> the start address. This is the information that is needed later in
> nuc900_i2c_remove to release the region. The field ioarea is also printed
> in some debugging code.
>
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression x,E;
> @@
> (
> *x = request_region(...)
>
> *x = request_mem_region(...)
> )
> ... when != release_region(x)
> when != x = E
> * release_resource(x);
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@diku.dk>
>
> ---
> Not compiled due to incompatible architecture.
>
> drivers/i2c/busses/i2c-nuc900.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-nuc900.c
> b/drivers/i2c/busses/i2c-nuc900.c index 7243426..97b16b7 100644
> --- a/drivers/i2c/busses/i2c-nuc900.c
> +++ b/drivers/i2c/busses/i2c-nuc900.c
> @@ -568,15 +568,13 @@ static int __devinit nuc900_i2c_probe(struct
> platform_device *pdev) goto err_clk;
> }
>
> - i2c->ioarea = request_mem_region(res->start, resource_size(res),
> - pdev->name);
> -
> - if (i2c->ioarea == NULL) {
> + if (!request_mem_region(res->start, resource_size(res), pdev->name)) {

I prefer the original version here -- it's clearer and also, doesn't the new
version violate line-over-80 principle ?

> dev_err(&pdev->dev, "cannot request IO\n");
> ret = -ENXIO;
> goto err_clk;
> }
>
> + i2c->ioarea = res;
> i2c->regs = ioremap(res->start, resource_size(res));
>
> if (i2c->regs == NULL) {
> @@ -645,8 +643,7 @@ static int __devinit nuc900_i2c_probe(struct
> platform_device *pdev) iounmap(i2c->regs);
>
> err_ioarea:
> - release_resource(i2c->ioarea);
> - kfree(i2c->ioarea);
> + release_mem_region(res->start, resource_size(res));
>
> err_clk:
> clk_disable(i2c->clk);
> @@ -665,6 +662,7 @@ static int __devinit nuc900_i2c_probe(struct
> platform_device *pdev) static int __devexit nuc900_i2c_remove(struct
> platform_device *pdev) {
> struct nuc900_i2c *i2c = platform_get_drvdata(pdev);
> + struct resource *res = i2c->ioarea;

No need for this ...
>
> i2c_del_adapter(&i2c->adap);
> free_irq(i2c->irq, i2c);
> @@ -674,8 +672,7 @@ static int __devexit nuc900_i2c_remove(struct
> platform_device *pdev)
>
> iounmap(i2c->regs);
>
> - release_resource(i2c->ioarea);
> - kfree(i2c->ioarea);

... the i2c pointer is still available here, why introducing struct resource
*res. release_mem_region() looks like a sane change to me though.

> + release_mem_region(res->start, resource_size(res));
> kfree(i2c);
>
> return 0;


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