[PATCH] drm/msm: Move call to PTR_ERR_OR_ZERO after reassignment

[PATCH] drm/msm: Move call to PTR_ERR_OR_ZERO after reassignment

[Vaishali Thakkar]

Here, a location is reset to NULL before being passed to PTR_ERR.
So, PTR_ERR should be called before its argument is reassigned
to NULL. Further to simplify things use PTR_ERR_OR_ZERO instead
of PTR_ERR and IS_ERR.

Problem found using Coccinelle.

Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
---
 drivers/gpu/drm/msm/edp/edp_ctrl.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/edp/edp_ctrl.c b/drivers/gpu/drm/msm/edp/edp_ctrl.c
index 81200e9..7816541 100644
--- a/drivers/gpu/drm/msm/edp/edp_ctrl.c
+++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c
@@ -302,21 +302,23 @@ static void edp_clk_disable(struct edp_ctrl *ctrl, u32 clk_mask)
 static int edp_regulator_init(struct edp_ctrl *ctrl)
 {
 	struct device *dev = &ctrl->pdev->dev;
+	int ret;
 
 	DBG("");
 	ctrl->vdda_vreg = devm_regulator_get(dev, "vdda");
-	if (IS_ERR(ctrl->vdda_vreg)) {
+	ret = PTR_ERR_OR_ZERO(ctrl->vdda_vreg);
+	if (ret) {
 		pr_err("%s: Could not get vdda reg, ret = %ld\n", __func__,
-				PTR_ERR(ctrl->vdda_vreg));
+				ret);
 		ctrl->vdda_vreg = NULL;
-		return PTR_ERR(ctrl->vdda_vreg);
+		return ret;
 	}
 	ctrl->lvl_vreg = devm_regulator_get(dev, "lvl-vdd");
-	if (IS_ERR(ctrl->lvl_vreg)) {
-		pr_err("Could not get lvl-vdd reg, %ld",
-				PTR_ERR(ctrl->lvl_vreg));
+	ret = PTR_ERR_OR_ZERO(ctrl->lvl_vreg);
+	if (ret) {
+		pr_err("Could not get lvl-vdd reg, %ld", ret);
 		ctrl->lvl_vreg = NULL;
-		return PTR_ERR(ctrl->lvl_vreg);
+		return ret;
 	}
 
 	return 0;
-- 
2.1.4

Re: [PATCH] drm/msm: Move call to PTR_ERR_OR_ZERO after reassignment

[Eric Engestrom]

On Wed, Apr 27, 2016 at 04:51:37PM +0530, Vaishali Thakkar wrote:
> Here, a location is reset to NULL before being passed to PTR_ERR.
> So, PTR_ERR should be called before its argument is reassigned
> to NULL. Further to simplify things use PTR_ERR_OR_ZERO instead
> of PTR_ERR and IS_ERR.
> 
> Problem found using Coccinelle.
> 
> Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
> ---
>  drivers/gpu/drm/msm/edp/edp_ctrl.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/edp/edp_ctrl.c b/drivers/gpu/drm/msm/edp/edp_ctrl.c
> index 81200e9..7816541 100644
> --- a/drivers/gpu/drm/msm/edp/edp_ctrl.c
> +++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c
> @@ -302,21 +302,23 @@ static void edp_clk_disable(struct edp_ctrl *ctrl, u32 clk_mask)
>  static int edp_regulator_init(struct edp_ctrl *ctrl)
>  {
>  	struct device *dev = &ctrl->pdev->dev;
> +	int ret;
>  
>  	DBG("");
>  	ctrl->vdda_vreg = devm_regulator_get(dev, "vdda");
> -	if (IS_ERR(ctrl->vdda_vreg)) {
> +	ret = PTR_ERR_OR_ZERO(ctrl->vdda_vreg);
> +	if (ret) {
>  		pr_err("%s: Could not get vdda reg, ret = %ld\n", __func__,
> -				PTR_ERR(ctrl->vdda_vreg));
> +				ret);
>  		ctrl->vdda_vreg = NULL;
> -		return PTR_ERR(ctrl->vdda_vreg);
> +		return ret;
>  	}
>  	ctrl->lvl_vreg = devm_regulator_get(dev, "lvl-vdd");
> -	if (IS_ERR(ctrl->lvl_vreg)) {
> -		pr_err("Could not get lvl-vdd reg, %ld",
> -				PTR_ERR(ctrl->lvl_vreg));
> +	ret = PTR_ERR_OR_ZERO(ctrl->lvl_vreg);
> +	if (ret) {

While you're rewriting them, it might be worth making these two pr_err()
print the same format, e.g.:

	pr_err("%s: Could not get lvl-vdd reg, ret = %ld\n", __func__, ret);

> +		pr_err("Could not get lvl-vdd reg, %ld", ret);
>  		ctrl->lvl_vreg = NULL;
> -		return PTR_ERR(ctrl->lvl_vreg);
> +		return ret;
>  	}
>  
>  	return 0;
> -- 
> 2.1.4

Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>

Re: [PATCH] drm/msm: Move call to PTR_ERR_OR_ZERO after reassignment

[Vaishali Thakkar]

On Thursday 28 April 2016 06:23 PM, Eric Engestrom wrote:
> On Wed, Apr 27, 2016 at 04:51:37PM +0530, Vaishali Thakkar wrote:
>> Here, a location is reset to NULL before being passed to PTR_ERR.
>> So, PTR_ERR should be called before its argument is reassigned
>> to NULL. Further to simplify things use PTR_ERR_OR_ZERO instead
>> of PTR_ERR and IS_ERR.
>>
>> Problem found using Coccinelle.
>>
>> Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
>> ---
>>  drivers/gpu/drm/msm/edp/edp_ctrl.c | 16 +++++++++-------
>>  1 file changed, 9 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/edp/edp_ctrl.c b/drivers/gpu/drm/msm/edp/edp_ctrl.c
>> index 81200e9..7816541 100644
>> --- a/drivers/gpu/drm/msm/edp/edp_ctrl.c
>> +++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c
>> @@ -302,21 +302,23 @@ static void edp_clk_disable(struct edp_ctrl *ctrl, u32 clk_mask)
>>  static int edp_regulator_init(struct edp_ctrl *ctrl)
>>  {
>>  	struct device *dev = &ctrl->pdev->dev;
>> +	int ret;
>>  
>>  	DBG("");
>>  	ctrl->vdda_vreg = devm_regulator_get(dev, "vdda");
>> -	if (IS_ERR(ctrl->vdda_vreg)) {
>> +	ret = PTR_ERR_OR_ZERO(ctrl->vdda_vreg);
>> +	if (ret) {
>>  		pr_err("%s: Could not get vdda reg, ret = %ld\n", __func__,
>> -				PTR_ERR(ctrl->vdda_vreg));
>> +				ret);
>>  		ctrl->vdda_vreg = NULL;
>> -		return PTR_ERR(ctrl->vdda_vreg);
>> +		return ret;
>>  	}
>>  	ctrl->lvl_vreg = devm_regulator_get(dev, "lvl-vdd");
>> -	if (IS_ERR(ctrl->lvl_vreg)) {
>> -		pr_err("Could not get lvl-vdd reg, %ld",
>> -				PTR_ERR(ctrl->lvl_vreg));
>> +	ret = PTR_ERR_OR_ZERO(ctrl->lvl_vreg);
>> +	if (ret) {
> 
> While you're rewriting them, it might be worth making these two pr_err()
> print the same format, e.g.:
> 
> 	pr_err("%s: Could not get lvl-vdd reg, ret = %ld\n", __func__, ret);

Done, thanks.

>> +		pr_err("Could not get lvl-vdd reg, %ld", ret);
>>  		ctrl->lvl_vreg = NULL;
>> -		return PTR_ERR(ctrl->lvl_vreg);
>> +		return ret;
>>  	}
>>  
>>  	return 0;
>> -- 
>> 2.1.4
> 
> Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
> 

-- 
Vaishali