video: fbdev: imxfb: fix return value check in imxfb_probe()

[PATCH -next] video: fbdev: imxfb: fix return value check in imxfb_probe()

Posted by Yang Yingliang 3 years, 8 months ago

If devm_ioremap_resource() fails, it never return NULL, replace
NULL test with IS_ERR().

Fixes: b083c22d5114 ("video: fbdev: imxfb: Convert request_mem_region + ioremap to devm_ioremap_resource")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/video/fbdev/imxfb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/imxfb.c b/drivers/video/fbdev/imxfb.c
index c48477893dd0..d97d7456d15a 100644
--- a/drivers/video/fbdev/imxfb.c
+++ b/drivers/video/fbdev/imxfb.c
@@ -971,9 +971,9 @@ static int imxfb_probe(struct platform_device *pdev)
 	}
 
 	fbi->regs = devm_ioremap_resource(&pdev->dev, res);
-	if (fbi->regs == NULL) {
+	if (IS_ERR(fbi->regs)) {
 		dev_err(&pdev->dev, "Cannot map frame buffer registers\n");
-		ret = -ENOMEM;
+		ret = PTR_ERR(fbi->regs);
 		goto failed_ioremap;
 	}
 
-- 
2.25.1

Re: [PATCH -next] video: fbdev: imxfb: fix return value check in imxfb_probe()

Posted by Uwe Kleine-König 3 years, 8 months ago

Hello,

On Fri, Jul 29, 2022 at 10:41:34AM +0800, Yang Yingliang wrote:
> If devm_ioremap_resource() fails, it never return NULL, replace
> NULL test with IS_ERR().

Oh, thanks for cleanup up behind me. Did you find this using some static
analysis tool? I would consider it interesting and fair to mention this
in the commit log.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

Re: [PATCH -next] video: fbdev: imxfb: fix return value check in imxfb_probe()

Posted by Yang Yingliang 3 years, 8 months ago

Hi,

On 2022/7/31 7:18, Uwe Kleine-König wrote:
> Hello,
>
> On Fri, Jul 29, 2022 at 10:41:34AM +0800, Yang Yingliang wrote:
>> If devm_ioremap_resource() fails, it never return NULL, replace
>> NULL test with IS_ERR().
> Oh, thanks for cleanup up behind me. Did you find this using some static
> analysis tool? I would consider it interesting and fair to mention this
> in the commit log.
I found it by coccicheck like this:

@@
expression ret, E;
@@
ret = \(devm_ioremap_resource\)(...);
... when != ret = E
     when != IS_ERR(ret)
(
  ret == NULL || IS_ERR(ret)
|
  IS_ERR(ret) || ret == NULL
|
  ret != NULL && !IS_ERR(ret)
|
  !IS_ERR(ret) && ret != NULL
|
- ret == NULL
+ IS_ERR(ret)
|
- ret != NULL
+ !IS_ERR(ret)
)

Thanks,
Yang
>
> Best regards
> Uwe
>
>

Re: [PATCH -next] video: fbdev: imxfb: fix return value check in imxfb_probe()

Posted by Helge Deller 3 years, 8 months ago

On 7/29/22 04:41, Yang Yingliang wrote:
> If devm_ioremap_resource() fails, it never return NULL, replace
> NULL test with IS_ERR().
>
> Fixes: b083c22d5114 ("video: fbdev: imxfb: Convert request_mem_region + ioremap to devm_ioremap_resource")
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>

applied to fbdev git tree.

Thanks!
Helge

> ---
>  drivers/video/fbdev/imxfb.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/video/fbdev/imxfb.c b/drivers/video/fbdev/imxfb.c
> index c48477893dd0..d97d7456d15a 100644
> --- a/drivers/video/fbdev/imxfb.c
> +++ b/drivers/video/fbdev/imxfb.c
> @@ -971,9 +971,9 @@ static int imxfb_probe(struct platform_device *pdev)
>  	}
>
>  	fbi->regs = devm_ioremap_resource(&pdev->dev, res);
> -	if (fbi->regs == NULL) {
> +	if (IS_ERR(fbi->regs)) {
>  		dev_err(&pdev->dev, "Cannot map frame buffer registers\n");
> -		ret = -ENOMEM;
> +		ret = PTR_ERR(fbi->regs);
>  		goto failed_ioremap;
>  	}
>