Re:Re: [PATCH] drm/auth: Move master pointer from drm_device to drm_file

[马强 <maqianga@xxxxxxxxxxxxx>]

> That sounds like a bug. drm_file->master should be always the same -

> either you become a new stand-alone thing, our you get linked to the

> current master.

> 
> Or I'm completely missing what you're trying to fix here.

Now I have a bug, the soft cursor disappears when switching users.

debug it, the fpriv->is_master is found to be 0. 

The reason it is 0 is that switching the user frees pointer of drm_file, 

and creating a new pointer of drm_file, and setting master. 

However, since dev->master is non-0, 

drm_new_set_master() of the setting master function will not be executed.

--

Qiang Ma

On Thu, Jun 17, 2021 at 05:47:33PM +0800, Qiang Ma wrote:  
> The drm_file pointer clears to zero during multi-user switching,  
> so it needs to call drm_new_set_master for master pointer from drm_file.  
 
That sounds like a bug. drm_file->master should be always the same -  
either you become a new stand-alone thing, our you get linked to the  
current master.  
 
Or I'm completely missing what you're trying to fix here.  
-Daniel  
 
>  
> Signed-off-by: Qiang Ma <maqianga@xxxxxxxxxxxxx>  
> ---  
> drivers/gpu/drm/drm_auth.c | 2 +-  
> 1 file changed, 1 insertion(+), 1 deletion(-)  
>  
> diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c  
> index f2d46b7ac6f9..02431af6d0c5 100644  
> --- a/drivers/gpu/drm/drm_auth.c  
> +++ b/drivers/gpu/drm/drm_auth.c  
> @@ -302,7 +302,7 @@ int drm_master_open(struct drm_file *file_priv)  
> /* if there is no current master make this fd it, but do not create  
> * any master object for render clients */  
> mutex_lock(&dev->master_mutex);  
> - if (!dev->master)  
> + if (!file_priv->master)  
> ret = drm_new_set_master(dev, file_priv);  
> else  
> file_priv->master = drm_master_get(dev->master);  
> --  
> 2.20.1  
>  
>  
>  
 
--  
Daniel Vetter  
Software Engineer, Intel Corporation  
http://blog.ffwll.ch