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Commit f9a70823 authored by Johan Hovold's avatar Johan Hovold Committed by Rob Herring
Browse files

drm/msm: fix OF child-node lookup 



Use the new of_get_compatible_child() helper to lookup the legacy
pwrlevels child node instead of using of_find_compatible_node(), which
searches the entire tree from a given start node and thus can return an
unrelated (i.e.  non-child) node.

This also addresses a potential use-after-free (e.g. after probe
deferral) as the tree-wide helper drops a reference to its first
argument (i.e. the probed device's node).

While at it, also fix the related child-node reference leak.

Fixes: e2af8b6b ("drm/msm: gpu: Use OPP tables if we can")
Cc: stable <stable@vger.kernel.org>     # 4.12
Cc: Jordan Crouse <jcrouse@codeaurora.org>
Cc: Rob Clark <robdclark@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent ceff2f4d

drivers/gpu/drm/msm/adreno/adreno_gpu.c

+3 −2
Original line number Diff line number Diff line
@@ -633,8 +633,7 @@ static int adreno_get_legacy_pwrlevels(struct device *dev) 
	struct device_node *child, *node;

	int ret;



	node = of_find_compatible_node(dev->of_node, NULL,

		"qcom,gpu-pwrlevels");

	node = of_get_compatible_child(dev->of_node, "qcom,gpu-pwrlevels");

	if (!node) {

		dev_err(dev, "Could not find the GPU powerlevels\n");

		return -ENXIO;
@@ -655,6 +654,8 @@ static int adreno_get_legacy_pwrlevels(struct device *dev) 
			dev_pm_opp_add(dev, val, 0);

	}



	of_node_put(node);



	return 0;

}