Re: [PATCH] soc/tegra: pmc: fix child-node lookup

From: Mikko Perttunen
Date: Thu Nov 16 2017 - 06:40:46 EST

On 15.11.2017 11:44, Johan Hovold wrote:
Fix child-node lookup during probe, which ended up searching the whole
device tree depth-first starting at the parent rather than just matching
on its children.

To make things worse, the parent pmc node could end up being prematurely
freed as of_find_node_by_name() drops a reference to its first argument.

Fixes: 3568df3d31d6 ("soc: tegra: Add thermal reset (thermtrip) support to PMC")
Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.0
Cc: Mikko Perttunen <mperttunen@xxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
drivers/soc/tegra/pmc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index 0453ff6839a7..7e9ef3431bea 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -1321,7 +1321,7 @@ static void tegra_pmc_init_tsense_reset(struct tegra_pmc *pmc)
if (!pmc->soc->has_tsense_reset)

- np = of_find_node_by_name(pmc->dev->of_node, "i2c-thermtrip");
+ np = of_get_child_by_name(pmc->dev->of_node, "i2c-thermtrip");
if (!np) {
dev_warn(dev, "i2c-thermtrip node not found, %s.\n", disabled);

Good find!

Reviewed-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>