Re: [PATCH v2] pmdomain: mtk-pm-domains: improve spinlock recursion fix in probe with correcting reference count

On Fri, 28 Nov 2025 at 05:17, Macpaul Lin macpaul.lin@mediatek.com wrote:

Remove scpsys_get_legacy_regmap(), replacing its usage with of_find_node_with_property(). Explicitly call of_node_get(np) before each of_find_node_with_property() to maintain correct node reference counting.

The of_find_node_with_property() function "consumes" its input by calling of_node_put() internally, whether or not it finds a match. Currently, dev->of_node (np) is passed multiple times in sequence without incrementing its reference count, causing it to be decremented multiple times and risking early memory release.

Adding of_node_get(np) before each call balances the reference count, preventing premature node release.

Fixes: c1bac49fe91f ("pmdomains: mtk-pm-domains: Fix spinlock recursion in probe") Cc: Stable@vger.kernel.org Signed-off-by: Macpaul Lin macpaul.lin@mediatek.com Tested-by: Louis-Alexis Eyraud louisalexis.eyraud@collabora.com

Applied for fixes, thanks!

Kind regards Uffe

---

drivers/pmdomain/mediatek/mtk-pm-domains.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-)

Changes for v2:

• Rewording commit message.
• Add Fixes: and Tested-by: tag, thanks.

diff --git a/drivers/pmdomain/mediatek/mtk-pm-domains.c b/drivers/pmdomain/mediatek/mtk-pm-domains.c index 80561d27f2b2..f64f24d520dd 100644 --- a/drivers/pmdomain/mediatek/mtk-pm-domains.c +++ b/drivers/pmdomain/mediatek/mtk-pm-domains.c @@ -984,18 +984,6 @@ static void scpsys_domain_cleanup(struct scpsys *scpsys) } }

-static struct device_node *scpsys_get_legacy_regmap(struct device_node *np, const char *pn) -{

•   struct device_node *local_node;
  

•   for_each_child_of_node(np, local_node) {
  

•           if (of_property_present(local_node, pn))
  

•                   return local_node;
  

•   }
  

•   return NULL;
  

-}

static int scpsys_get_bus_protection_legacy(struct device *dev, struct scpsys *scpsys) { const u8 bp_blocks[3] = { @@ -1017,7 +1005,8 @@ static int scpsys_get_bus_protection_legacy(struct device *dev, struct scpsys *s * this makes it then possible to allocate the array of bus_prot * regmaps and convert all to the new style handling. */

•   node = scpsys_get_legacy_regmap(np, "mediatek,infracfg");
  

•   of_node_get(np);
  

•   node = of_find_node_with_property(np, "mediatek,infracfg");
    if (node) {
            regmap[0] = syscon_regmap_lookup_by_phandle(node, "mediatek,infracfg");
            of_node_put(node);
  

@@ -1030,7 +1019,8 @@ static int scpsys_get_bus_protection_legacy(struct device *dev, struct scpsys *s regmap[0] = NULL; }

•   node = scpsys_get_legacy_regmap(np, "mediatek,smi");
  

•   of_node_get(np);
  

•   node = of_find_node_with_property(np, "mediatek,smi");
    if (node) {
            smi_np = of_parse_phandle(node, "mediatek,smi", 0);
            of_node_put(node);
  

@@ -1048,7 +1038,8 @@ static int scpsys_get_bus_protection_legacy(struct device *dev, struct scpsys *s regmap[1] = NULL; }

•   node = scpsys_get_legacy_regmap(np, "mediatek,infracfg-nao");
  

•   of_node_get(np);
  

•   node = of_find_node_with_property(np, "mediatek,infracfg-nao");
    if (node) {
            regmap[2] = syscon_regmap_lookup_by_phandle(node, "mediatek,infracfg-nao");
            num_regmaps++;
  

-- 2.45.2