Re: [CI] drm: Ensure ioctls are drained before device unplug

[Matthew Brost <matthew.brost@intel.com>]

On Tue, Apr 14, 2026 at 11:15:52AM +0200, Thomas Hellström wrote:
> There is a check that blocks ioctls after device unplug,
> but we have no check that running ioctls have actually
> completed at unplug time. (And for some IOCTLs like
> fence waits, that actually makes sense).
> However, implement ioctl draining to have CI check for
> lockdep issues.
> 
> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>


CI patch, but this seems entirely correct—unless there’s some black
magic or hand-wavy behavior involved for not protecting IOCTLs against
unplug.

So…

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
>  drivers/gpu/drm/drm_ioctl.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index ff193155129e..c87a925f0fe4 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -789,19 +789,22 @@ long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
>  {
>  	struct drm_file *file_priv = file->private_data;
>  	struct drm_device *dev = file_priv->minor->dev;
> -	int ret;
> +	int ret, idx;
>  
>  	/* Update drm_file owner if fd was passed along. */
>  	drm_file_update_pid(file_priv);
>  
> -	if (drm_dev_is_unplugged(dev))
> +	if (!drm_dev_enter(dev, &idx))
>  		return -ENODEV;
>  
>  	ret = drm_ioctl_permit(flags, file_priv);
>  	if (unlikely(ret))
> -		return ret;
> +		goto out;
>  
> -	return func(dev, kdata, file_priv);
> +	ret = func(dev, kdata, file_priv);
> + out:
> +	drm_dev_exit(idx);
> +	return ret;
>  }
>  EXPORT_SYMBOL(drm_ioctl_kernel);
>  
> -- 
> 2.53.0
>