Re: [PATCH 1/6] drivers: base: devres: Allow to release group on device release

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Feb 20, 2025 at 05:48:10PM -0600, Lucas De Marchi wrote:
> On Thu, Feb 20, 2025 at 01:24:20PM +0100, Greg Kroah-Hartman wrote:
> > On Wed, Feb 12, 2025 at 12:05:37PM -0800, Lucas De Marchi wrote:
> > > When releasing a device, if the release action causes a group to be
> > > released, a warning is emitted because it can't find the group. This
> > > happens because devres_release_all() moves the entire list to a todo
> > > list and also move the group markers. Considering r* normal resource
> > > nodes and g1 a group resource node:
> > > 
> > > 		    g1 -----------.
> > > 		    v		  v
> > > 	r1 -> r2 -> g1[0] -> r3-> g[1] -> r4
> > > 
> > > After devres_release_all(), dev->devres_head becomes empty and the todo
> > > list it iterates on becomes:
> > > 
> > > 			       g1
> > > 			       v
> > > 	r1 -> r2 -> r3-> r4 -> g1[0]
> > > 
> > > When a call to component_del() is made and takes down the aggregate
> > > device, a warning like this happen:
> > > 
> > > 	RIP: 0010:devres_release_group+0x362/0x530
> > > 	...
> > > 	Call Trace:
> > > 	 <TASK>
> > > 	 component_unbind+0x156/0x380
> > > 	 component_unbind_all+0x1d0/0x270
> > > 	 mei_component_master_unbind+0x28/0x80 [mei_hdcp]
> > > 	 take_down_aggregate_device+0xc1/0x160
> > > 	 component_del+0x1c6/0x3e0
> > > 	 intel_hdcp_component_fini+0xf1/0x170 [xe]
> > > 	 xe_display_fini+0x1e/0x40 [xe]
> > > 
> > > Because the devres group corresponding to the hdcp component cannot be
> > > found. Just ignore this corner case: if the dev->devres_head is empty
> > > and the caller is trying to remove a group, it's likely in the process
> > > of device cleanup so just ignore it instead of warning.
> > > 
> > > Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
> > > ---
> > 
> > Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> Thanks. Is it ok to take these 3 through the drm tree or are you taking
> it through yours?

As the drm patches depened on these, I figured they should all go
through the drm tree, so please feel free to take them.

thanks,

greg k-h