The rk_udphy_clk_init() function would currently try to do a strncmp for
a NULL pointer, if DT specifies 'clocks' property, but no 'clock-names'
property. Fix this by making sure the clock has an id string set.

Note that DT binding requires setting clock-names, so this is only a
problem when booting a non-compliant device tree.

Fixes: 2f70bbddeb45 ("phy: rockchip: add usbdp combo phy driver")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/message/20260619154349.071321F000E9%40smtp.kernel.org
Signed-off-by: Sebastian Reichel <redacted>
---
 drivers/phy/rockchip/phy-rockchip-usbdp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/phy/rockchip/phy-rockchip-usbdp.c b/drivers/phy/rockchip/phy-rockchip-usbdp.c
index 2845a012eafc..3fc8222fcaec 100644
--- a/drivers/phy/rockchip/phy-rockchip-usbdp.c
+++ b/drivers/phy/rockchip/phy-rockchip-usbdp.c

@@ -432,6 +432,9 @@ static int rk_udphy_clk_init(struct rk_udphy *udphy, struct device *dev)
 
 	/* used for configure phy reference clock frequency */
 	for (i = 0; i < udphy->num_clks; i++) {
+		if (!udphy->clks[i].id)
+			continue;
+
 		if (!strncmp(udphy->clks[i].id, "refclk", 6)) {
 			udphy->refclk = udphy->clks[i].clk;
 			break;

-- 
2.53.0