Re: [PATCH] drm: remove duplicate check on parent and avoid BUG_ON

From: Daniel Vetter
Date: Tue Dec 17 2019 - 08:13:45 EST


On Sun, Dec 15, 2019 at 01:43:44PM -0600, Aditya Pakki wrote:
> In drm_dev_init, parent is checked for NULL via assert after
> checked in devm_drm_dev_init(). The patch removes the duplicate
> check and replaces the assertion with WARN_ON. Further, it returns
> -EINVAL consistent with the usage in devm_drm_dev_init.
>
> Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>

Makes sense, patch applied to drm-misc-next.

Thanks, Daniel

> ---
> drivers/gpu/drm/drm_drv.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 1b9b40a1c7c9..7c18a980cd4b 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -622,7 +622,8 @@ int drm_dev_init(struct drm_device *dev,
> return -ENODEV;
> }
>
> - BUG_ON(!parent);
> + if (WARN_ON(!parent))
> + return -EINVAL;
>
> kref_init(&dev->ref);
> dev->dev = get_device(parent);
> @@ -725,7 +726,7 @@ int devm_drm_dev_init(struct device *parent,
> {
> int ret;
>
> - if (WARN_ON(!parent || !driver->release))
> + if (WARN_ON(!driver->release))
> return -EINVAL;
>
> ret = drm_dev_init(dev, driver, parent);
> --
> 2.20.1
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch