phy: hisilicon: fix UTMI reset leaks in INNO USB2 PHY

hisi_inno_phy_probe() acquires an exclusive UTMI reset control for each child node but never releases it on probe failure or driver detach. The leaked controls remain acquired, so a later probe can fail with -EBUSY when requesting the same resets.

Register a devres action after each successful lookup to release the control on probe failure and detach.

Found during source review of reset-control lifetimes.

Build-tested the driver object on x86_64 with W=1 and reset support enabled. No hardware testing.

---
 drivers/phy/hisilicon/phy-hisi-inno-usb2.c | 9 +++++++++
 1 file changed, 9 insertions(+)

index c843923252aa..9bf207e3e692 100644
@@ -132,6 +132,11 @@ static const struct phy_ops hisi_inno_phy_ops = {
 	.owner = THIS_MODULE,
 };
 
+static void hisi_inno_phy_reset_put(void *data)
+{
+	reset_control_put(data);
+}
+
 static int hisi_inno_phy_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;

@@ -169,6 +174,10 @@ static int hisi_inno_phy_probe(struct platform_device *pdev)
 		if (IS_ERR(rst))
 			return PTR_ERR(rst);
 
+		ret = devm_add_action_or_reset(dev, hisi_inno_phy_reset_put, rst);
+		if (ret)
+			return ret;
+
 		priv->ports[i].utmi_rst = rst;
 		priv->ports[i].priv = priv;
 

base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4

It looks like an equivalent to devm_get_clk_from_child() for reset controls could be useful.

regards
Philipp

Hi Philipp,

Thanks for the review.

Regarding your suggestion about a from_child equivalent, I checked the reset core after your reply. The existing devm reset-control helpers don't provide a way to obtain a reset control from an explicit child device node. I agree that such a helper would be useful.

Do you have a particular API design in mind? If you're not already planning to work on this, I'd be happy to study the reset core and explore a separate follow-up patch. No timeline yet.

For the current fix, I plan to keep the change self-contained in this driver.

Best regards,
Xia Yan

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