The debugfs_create_dir() function returns error pointers.
It never returns NULL. So use IS_ERR() to check it.

Signed-off-by: Yang Ruibin <11162571@vivo.com>
---
 drivers/media/pci/mgb4/mgb4_vin.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/pci/mgb4/mgb4_vin.c b/drivers/media/pci/mgb4/mgb4_vin.c
index e9332abb3172..808eb51b270c 100644
--- a/drivers/media/pci/mgb4/mgb4_vin.c
+++ b/drivers/media/pci/mgb4/mgb4_vin.c
@@ -860,7 +860,7 @@ static void debugfs_init(struct mgb4_vin_dev *vindev)
 
 	vindev->debugfs = debugfs_create_dir(vindev->vdev.name,
 					     vindev->mgbdev->debugfs);
-	if (!vindev->debugfs)
+	if (IS_ERR(vindev->debugfs))
 		return;
 
 	vindev->regs[0].name = "CONFIG";
-- 
2.34.1

On 21. 08. 24 9:29 dop., Yang Ruibin wrote:
> The debugfs_create_dir() function returns error pointers.
> It never returns NULL. So use IS_ERR() to check it.
> 
> Signed-off-by: Yang Ruibin <11162571@vivo.com>
> ---
>   drivers/media/pci/mgb4/mgb4_vin.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/pci/mgb4/mgb4_vin.c b/drivers/media/pci/mgb4/mgb4_vin.c
> index e9332abb3172..808eb51b270c 100644
> --- a/drivers/media/pci/mgb4/mgb4_vin.c
> +++ b/drivers/media/pci/mgb4/mgb4_vin.c
> @@ -860,7 +860,7 @@ static void debugfs_init(struct mgb4_vin_dev *vindev)
>   
>   	vindev->debugfs = debugfs_create_dir(vindev->vdev.name,
>   					     vindev->mgbdev->debugfs);
> -	if (!vindev->debugfs)
> +	if (IS_ERR(vindev->debugfs))
>   		return;
>   
>   	vindev->regs[0].name = "CONFIG";

Superseded by
 
https://patchwork.linuxtv.org/project/linux-media/patch/20240826132604.3240-2-tumic@gpxsee.org/
that handles both the input/output device cases as well as an error when 
creating the parent mgb4(PCIe) device.

M.

On 21. 08. 24 9:29 dop., Yang Ruibin wrote:
> The debugfs_create_dir() function returns error pointers.
> It never returns NULL. So use IS_ERR() to check it.
> 
> Signed-off-by: Yang Ruibin <11162571@vivo.com>
> ---
>   drivers/media/pci/mgb4/mgb4_vin.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/pci/mgb4/mgb4_vin.c b/drivers/media/pci/mgb4/mgb4_vin.c
> index e9332abb3172..808eb51b270c 100644
> --- a/drivers/media/pci/mgb4/mgb4_vin.c
> +++ b/drivers/media/pci/mgb4/mgb4_vin.c
> @@ -860,7 +860,7 @@ static void debugfs_init(struct mgb4_vin_dev *vindev)
>   
>   	vindev->debugfs = debugfs_create_dir(vindev->vdev.name,
>   					     vindev->mgbdev->debugfs);
> -	if (!vindev->debugfs)
> +	if (IS_ERR(vindev->debugfs))
>   		return;
>   
>   	vindev->regs[0].name = "CONFIG";

Reviewed-by: Martin Tůma <martin.tuma@digiteqautomotive.com>