linux-kernel - [PATCH] phy: core: Reinstate pm_runtime_enabled() check in phy_pm_runtime

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Message-ID: <3ca9f8166d21685bfbf97535da30172f74822130.1767107014.git.geert+renesas@glider.be>
Date: Tue, 30 Dec 2025 16:04:05 +0100
From: Geert Uytterhoeven <geert+renesas@...der.be>
To: Vinod Koul <vkoul@...nel.org>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>
Cc: linux-phy@...ts.infradead.org,
	linux-renesas-soc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH] phy: core: Reinstate pm_runtime_enabled() check in phy_pm_runtime_put()

On Koelsch (R-Car M2-W), during boot and s2ram:

    phy phy-e6590100.usb-phy-controller.0: Runtime PM usage count underflow!

While phy_pm_runtime_get{,_sync}() and phy_pm_runtime_put_sync() still
contain pm_runtime_enabled() checks, the same check in
phy_pm_runtime_put() was deemed redundant and removed, causing count
underflows with PHY drivers like drivers/phy/renesas/phy-rcar-gen2.c
that do not use Runtime PM yet,

Fix this by reinstating the check.

Fixes: caad07ae07e3fb17 ("phy: core: Discard pm_runtime_put() return values")
Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
---
 drivers/phy/phy-core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index 160ecb757d1d62a0..e2a2a99d069789c7 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -195,6 +195,9 @@ void phy_pm_runtime_put(struct phy *phy)
 	if (!phy)
 		return;
 
+	if (!pm_runtime_enabled(&phy->dev))
+		return;
+
 	pm_runtime_put(&phy->dev);
 }
 EXPORT_SYMBOL_GPL(phy_pm_runtime_put);
-- 
2.43.0