Re: [PATCH -next] mtd: docg3: Fix passing zero to 'PTR_ERR' warning in doc_probe_device

[Boris Brezillon <bbrezillon@kernel.org>]

On Wed, 23 Jan 2019 14:58:27 +0800
YueHaibing <yuehaibing@huawei.com> wrote:

> Fix a static code checker warning:
> drivers/mtd/devices/docg3.c:1875
>  doc_probe_device() warn: passing zero to 'ERR_PTR'
> 
> Fixes: ae9d4934b2d7 ("mtd: docg3: add multiple floor support")
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
> ---
>  drivers/mtd/devices/docg3.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
> index 4c94fc0..60ddc38 100644
> --- a/drivers/mtd/devices/docg3.c
> +++ b/drivers/mtd/devices/docg3.c
> @@ -1872,7 +1872,7 @@ doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
>  nomem2:
>  	kfree(docg3);
>  nomem1:
> -	return ERR_PTR(ret);
> +	return ret ? ERR_PTR(ret) : NULL;
>  }
>  

This is not the right fix, you should instead set ret to -EINVAL:

--->8---
diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index 4c94fc096696..6b84db411232 100644
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -1842,7 +1842,7 @@ doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
        chip_id = doc_register_readw(docg3, DOC_CHIPID);
        chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);
 
-       ret = 0;
+       ret = -ENOMEM;
        if (chip_id != (u16)(~chip_id_inv)) {
                goto nomem4;
        }