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drivers: base: devres: Allow to release group on device release

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[ Upstream commit 8e1ddfada4530939a8cb64ee9251aef780474274 ]

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.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250222001051.3012936-2-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Lucas De Marchi
2025-02-21 16:10:41 -08:00
committed by Greg Kroah-Hartman
parent c9323cbc94
commit 1c38108a49
1 changed files with 7 additions and 0 deletions
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7
drivers/base/devres.c
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@@ -687,6 +687,13 @@ int devres_release_group(struct device *dev, void *id)
spin_unlock_irqrestore(&dev->devres_lock, flags);
release_nodes(dev, &todo);
} else if (list_empty(&dev->devres_head)) {
/*
* dev is probably dying via devres_release_all(): groups
* have already been removed and are on the process of
* being released - don't touch and don't warn.
*/
spin_unlock_irqrestore(&dev->devres_lock, flags);
} else {
WARN_ON(1);
spin_unlock_irqrestore(&dev->devres_lock, flags);