2014-01-21 05:21:25

by Lad, Prabhakar

Subject: [PATCH v2] media: i2c: mt9p031: Check return value of clk_prepare_enable/clk_set_rate

From: "Lad, Prabhakar" <[email protected]>

clk_set_rate(), clk_prepare_enable() functions can fail, so check the return
values to avoid surprises.

Signed-off-by: Lad, Prabhakar <[email protected]>
---
Changes for v2:
1: Called regulator_bulk_disable() in the error path

drivers/media/i2c/mt9p031.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c
index e5ddf47..05278f5 100644
--- a/drivers/media/i2c/mt9p031.c
+++ b/drivers/media/i2c/mt9p031.c
@@ -222,12 +222,15 @@ static int mt9p031_clk_setup(struct mt9p031 *mt9p031)

struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
struct mt9p031_platform_data *pdata = mt9p031->pdata;
+ int ret;

mt9p031->clk = devm_clk_get(&client->dev, NULL);
if (IS_ERR(mt9p031->clk))
return PTR_ERR(mt9p031->clk);

- clk_set_rate(mt9p031->clk, pdata->ext_freq);
+ ret = clk_set_rate(mt9p031->clk, pdata->ext_freq);
+ if (ret < 0)
+ return ret;

mt9p031->pll.ext_clock = pdata->ext_freq;
mt9p031->pll.pix_clock = pdata->target_freq;
@@ -286,8 +289,14 @@ static int mt9p031_power_on(struct mt9p031 *mt9p031)
return ret;

/* Emable clock */
- if (mt9p031->clk)
- clk_prepare_enable(mt9p031->clk);
+ if (mt9p031->clk) {
+ ret = clk_prepare_enable(mt9p031->clk);
+ if (ret) {
+ regulator_bulk_disable(ARRAY_SIZE(mt9p031->regulators),
+ mt9p031->regulators);
+ return ret;
+ }
+ }

/* Now RESET_BAR must be high */
if (gpio_is_valid(mt9p031->reset)) {
--
1.7.9.5

2014-01-21 11:18:16

by Laurent Pinchart

Subject: Re: [PATCH v2] media: i2c: mt9p031: Check return value of clk_prepare_enable/clk_set_rate

Hi Prabhakar,

Thank you for the patch.

On Tuesday 21 January 2014 10:50:57 Prabhakar Lad wrote:
> From: "Lad, Prabhakar" <[email protected]>
>
> clk_set_rate(), clk_prepare_enable() functions can fail, so check the return
> values to avoid surprises.
>
> Signed-off-by: Lad, Prabhakar <[email protected]>

Acked-by: Laurent Pinchart <[email protected]>

and applied to my tree.

> ---
> Changes for v2:
> 1: Called regulator_bulk_disable() in the error path
>
> drivers/media/i2c/mt9p031.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c
> index e5ddf47..05278f5 100644
> --- a/drivers/media/i2c/mt9p031.c
> +++ b/drivers/media/i2c/mt9p031.c
> @@ -222,12 +222,15 @@ static int mt9p031_clk_setup(struct mt9p031 *mt9p031)
>
> struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
> struct mt9p031_platform_data *pdata = mt9p031->pdata;
> + int ret;
>
> mt9p031->clk = devm_clk_get(&client->dev, NULL);
> if (IS_ERR(mt9p031->clk))
> return PTR_ERR(mt9p031->clk);
>
> - clk_set_rate(mt9p031->clk, pdata->ext_freq);
> + ret = clk_set_rate(mt9p031->clk, pdata->ext_freq);
> + if (ret < 0)
> + return ret;
>
> mt9p031->pll.ext_clock = pdata->ext_freq;
> mt9p031->pll.pix_clock = pdata->target_freq;
> @@ -286,8 +289,14 @@ static int mt9p031_power_on(struct mt9p031 *mt9p031)
> return ret;
>
> /* Emable clock */
> - if (mt9p031->clk)
> - clk_prepare_enable(mt9p031->clk);
> + if (mt9p031->clk) {
> + ret = clk_prepare_enable(mt9p031->clk);
> + if (ret) {
> + regulator_bulk_disable(ARRAY_SIZE(mt9p031->regulators),
> + mt9p031->regulators);
> + return ret;
> + }
> + }
>
> /* Now RESET_BAR must be high */
> if (gpio_is_valid(mt9p031->reset)) {

--
Regards,

Laurent Pinchart