2011-02-03 17:17:26

by Julia Lawall

[permalink] [raw]
Subject: [PATCH] drivers/w1/masters/omap_hdq.c: Add missing clk_put

This code makes two calls to clk_get, then test both return values
and fails if either failed. The problem is that in the first inner if,
where the first call to clk_get has failed, it don't know if the second
call has failed as well. So it don't know whether clk_get should be called
on the result of the second call. Of course, it would be possible to test
that value again. A simpler solution is just to test the result of calling
clk_get directly after each call.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
position p1,p2;
expression e;
statement S;
@@

e = clk_get@p1(...)
...
if@p2 (IS_ERR(e)) S

@@
expression e;
statement S;
identifier l;
position r.p1, p2 != r.p2;
@@

*e = clk_get@p1(...)
... when != clk_put(e)
*if@p2 (...)
{
... when != clk_put(e)
* return ...;
}// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---
drivers/w1/masters/omap_hdq.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c
index 3a7e9ff..38e96ab 100644
--- a/drivers/w1/masters/omap_hdq.c
+++ b/drivers/w1/masters/omap_hdq.c
@@ -593,19 +593,17 @@ static int __devinit omap_hdq_probe(struct platform_device *pdev)

/* get interface & functional clock objects */
hdq_data->hdq_ick = clk_get(&pdev->dev, "ick");
- hdq_data->hdq_fck = clk_get(&pdev->dev, "fck");
+ if (IS_ERR(hdq_data->hdq_ick)) {
+ dev_dbg(&pdev->dev, "Can't get HDQ ick clock object\n");
+ ret = PTR_ERR(hdq_data->hdq_ick);
+ goto err_ick;
+ }

- if (IS_ERR(hdq_data->hdq_ick) || IS_ERR(hdq_data->hdq_fck)) {
- dev_dbg(&pdev->dev, "Can't get HDQ clock objects\n");
- if (IS_ERR(hdq_data->hdq_ick)) {
- ret = PTR_ERR(hdq_data->hdq_ick);
- goto err_clk;
- }
- if (IS_ERR(hdq_data->hdq_fck)) {
- ret = PTR_ERR(hdq_data->hdq_fck);
- clk_put(hdq_data->hdq_ick);
- goto err_clk;
- }
+ hdq_data->hdq_fck = clk_get(&pdev->dev, "fck");
+ if (IS_ERR(hdq_data->hdq_fck)) {
+ dev_dbg(&pdev->dev, "Can't get HDQ fck clock object\n");
+ ret = PTR_ERR(hdq_data->hdq_fck);
+ goto err_fck;
}

hdq_data->hdq_usecount = 0;
@@ -665,10 +663,12 @@ err_fnclk:
clk_disable(hdq_data->hdq_ick);

err_intfclk:
- clk_put(hdq_data->hdq_ick);
clk_put(hdq_data->hdq_fck);

-err_clk:
+err_fck:
+ clk_put(hdq_data->hdq_ick);
+
+err_ick:
iounmap(hdq_data->hdq_base);

err_ioremap:


2011-02-07 07:59:41

by Amit Kucheria

[permalink] [raw]
Subject: Re: [PATCH] drivers/w1/masters/omap_hdq.c: Add missing clk_put

On 11 Feb 03, Julia Lawall wrote:
> This code makes two calls to clk_get, then test both return values
> and fails if either failed. The problem is that in the first inner if,
> where the first call to clk_get has failed, it don't know if the second
> call has failed as well. So it don't know whether clk_get should be called
> on the result of the second call. Of course, it would be possible to test
> that value again. A simpler solution is just to test the result of calling
> clk_get directly after each call.
>
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @r@
> position p1,p2;
> expression e;
> statement S;
> @@
>
> e = clk_get@p1(...)
> ...
> if@p2 (IS_ERR(e)) S
>
> @@
> expression e;
> statement S;
> identifier l;
> position r.p1, p2 != r.p2;
> @@
>
> *e = clk_get@p1(...)
> ... when != clk_put(e)
> *if@p2 (...)
> {
> ... when != clk_put(e)
> * return ...;
> }// </smpl>
>
> Signed-off-by: Julia Lawall <[email protected]>

Makes the code easier to read.

Acked-by: Amit Kucheria <[email protected]>

> ---
> drivers/w1/masters/omap_hdq.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c
> index 3a7e9ff..38e96ab 100644
> --- a/drivers/w1/masters/omap_hdq.c
> +++ b/drivers/w1/masters/omap_hdq.c
> @@ -593,19 +593,17 @@ static int __devinit omap_hdq_probe(struct platform_device *pdev)
>
> /* get interface & functional clock objects */
> hdq_data->hdq_ick = clk_get(&pdev->dev, "ick");
> - hdq_data->hdq_fck = clk_get(&pdev->dev, "fck");
> + if (IS_ERR(hdq_data->hdq_ick)) {
> + dev_dbg(&pdev->dev, "Can't get HDQ ick clock object\n");
> + ret = PTR_ERR(hdq_data->hdq_ick);
> + goto err_ick;
> + }
>
> - if (IS_ERR(hdq_data->hdq_ick) || IS_ERR(hdq_data->hdq_fck)) {
> - dev_dbg(&pdev->dev, "Can't get HDQ clock objects\n");
> - if (IS_ERR(hdq_data->hdq_ick)) {
> - ret = PTR_ERR(hdq_data->hdq_ick);
> - goto err_clk;
> - }
> - if (IS_ERR(hdq_data->hdq_fck)) {
> - ret = PTR_ERR(hdq_data->hdq_fck);
> - clk_put(hdq_data->hdq_ick);
> - goto err_clk;
> - }
> + hdq_data->hdq_fck = clk_get(&pdev->dev, "fck");
> + if (IS_ERR(hdq_data->hdq_fck)) {
> + dev_dbg(&pdev->dev, "Can't get HDQ fck clock object\n");
> + ret = PTR_ERR(hdq_data->hdq_fck);
> + goto err_fck;
> }
>
> hdq_data->hdq_usecount = 0;
> @@ -665,10 +663,12 @@ err_fnclk:
> clk_disable(hdq_data->hdq_ick);
>
> err_intfclk:
> - clk_put(hdq_data->hdq_ick);
> clk_put(hdq_data->hdq_fck);
>
> -err_clk:
> +err_fck:
> + clk_put(hdq_data->hdq_ick);
> +
> +err_ick:
> iounmap(hdq_data->hdq_base);
>
> err_ioremap:
>

--
----------------------------------------------------------------------
Amit Kucheria, Kernel Engineer || [email protected]
----------------------------------------------------------------------

2011-02-10 03:14:34

by Tony Lindgren

[permalink] [raw]
Subject: Re: [PATCH] drivers/w1/masters/omap_hdq.c: Add missing clk_put

* Amit Kucheria <[email protected]> [110206 23:58]:
> >
> > Signed-off-by: Julia Lawall <[email protected]>
>
> Makes the code easier to read.
>
> Acked-by: Amit Kucheria <[email protected]>

Acked-by: Tony Lindgren <[email protected]>