Re: [PATCH] media: mgb4: Fix double debugfs remove

From: Hans Verkuil
Date: Mon May 27 2024 - 03:37:09 EST


Hi Martin,

On 21/05/2024 18:22, tumic@xxxxxxxxxx wrote:
> From: Martin Tůma <martin.tuma@xxxxxxxxxxxxxxxxxxxxx>
>
> Fixes an error where debugfs_remove_recursive() is called first on a parent
> directory and then again on a child which causes a kernel panic.

I accepted this patch for v6.10, but I would appreciate it if you can
make an additional patch for v6.11 that removes the #ifdef CONFIG_DEBUG_FS
lines where possible.

Most debugfs functions have a dummy implementation when that define is not
set, so it would clean up the driver if these unnecessary #ifdefs are removed.

Regards,

Hans

>
> Signed-off-by: Martin Tůma <martin.tuma@xxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/media/pci/mgb4/mgb4_core.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/pci/mgb4/mgb4_core.c b/drivers/media/pci/mgb4/mgb4_core.c
> index 60498a5abebf..ab4f07e2e560 100644
> --- a/drivers/media/pci/mgb4/mgb4_core.c
> +++ b/drivers/media/pci/mgb4/mgb4_core.c
> @@ -642,9 +642,6 @@ static void mgb4_remove(struct pci_dev *pdev)
> struct mgb4_dev *mgbdev = pci_get_drvdata(pdev);
> int i;
>
> -#ifdef CONFIG_DEBUG_FS
> - debugfs_remove_recursive(mgbdev->debugfs);
> -#endif
> #if IS_REACHABLE(CONFIG_HWMON)
> hwmon_device_unregister(mgbdev->hwmon_dev);
> #endif
> @@ -659,6 +656,10 @@ static void mgb4_remove(struct pci_dev *pdev)
> if (mgbdev->vin[i])
> mgb4_vin_free(mgbdev->vin[i]);
>
> +#ifdef CONFIG_DEBUG_FS
> + debugfs_remove_recursive(mgbdev->debugfs);
> +#endif
> +
> device_remove_groups(&mgbdev->pdev->dev, mgb4_pci_groups);
> free_spi(mgbdev);
> free_i2c(mgbdev);
>
> base-commit: 8771b7f31b7fff91a998e6afdb60650d4bac59a5