2016-04-27 11:22:03

by Vaishali Thakkar

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

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 <[email protected]>
---
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

2016-04-28 12:52:38

by Eric Engestrom

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

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 <[email protected]>
> ---
> 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 <[email protected]>

2016-04-28 13:23:49

by Vaishali Thakkar

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

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 <[email protected]>
>> ---
>> 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 <[email protected]>
>

--
Vaishali