Re: [PATCH v12 28/36] phy: rockchip: usbdp: Only enable USB3 when not in high-speed mode
From: sashiko-bot@kernel.org
Date: 2026-07-10 21:26:17
Also in:
linux-devicetree
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: Pre-existing issues: - [High] rk_udphy_power_on returns 0 (success) for unsupported modes, tricking callers into accessing unclocked PHY registers --
--- Patch [28]: [PATCH v12 28/36] phy: rockchip: usbdp: Only enable USB3 when not in high-speed mode ---commit fac8dba407b679ba8fc75d417de958451d90f46f Author: Sebastian Reichel [off-list ref] phy: rockchip: usbdp: Only enable USB3 when not in high-speed mode Ensure that USB3 mode is not accidently enabled during PHY re-init for systems that are configured as high-speed only via DT. Closes: https://sashiko.dev/#/message/20260626212424.C215E1F000E9%40smtp.kernel.org
quoted hunk ↗ jump to hunk
diff --git a/drivers/phy/rockchip/phy-rockchip-usbdp.c b/drivers/phy/rockchip/phy-rockchip-usbdp.c index 2099ae2e51d1c..af915cc377275 100644 --- a/drivers/phy/rockchip/phy-rockchip-usbdp.c +++ b/drivers/phy/rockchip/phy-rockchip-usbdp.c@@ -1009,7 +1009,7 @@ static int rk_udphy_power_on(struct rk_udphy *udphy, u8 mode) if (ret) return ret;
[Severity: High]
This is a pre-existing issue, but I noticed a potential problem in how
rk_udphy_power_on() handles unsupported modes.
At the beginning of rk_udphy_power_on(), if the hardware isn't configured
for the requested mode, the function logs an info message and returns 0:
if (!(udphy->mode & mode)) {
dev_info(udphy->dev, "mode 0x%02x is not support\n", mode);
return 0;
}
Because it returns success, callers might assume the PHY was successfully
powered up and clocked. For example, if we look at rk_udphy_dp_phy_power_on():
ret = rk_udphy_power_on(udphy, UDPHY_MODE_DP);
if (ret)
return ret;
rk_udphy_dp_lane_enable(udphy, udphy->dp_lanes);
If UDPHY_MODE_DP is requested but not supported (for instance, if the
device tree configures it as USB-only), rk_udphy_power_on() will skip
the setup sequence and return 0.
Would the caller then proceed to access unclocked memory-mapped registers
in rk_udphy_dp_lane_enable() and trigger a kernel panic (SError)?
Should rk_udphy_power_on() return an error code like -EOPNOTSUPP instead
of 0 when an unsupported mode is requested?
- if (udphy->mode & UDPHY_MODE_USB)
+ if (!udphy->hs && udphy->mode & UDPHY_MODE_USB)
rk_udphy_u3_port_disable(udphy, false);
udphy->phy_needs_reinit = false;
} else if (udphy->phy_needs_reinit) {-- Sashiko AI review · https://sashiko.dev/#/patchset/20260710-rockchip-usbdp-cleanup-v12-0-8b41a9a9bef0@collabora.com?part=28 -- linux-phy mailing list linux-phy@lists.infradead.org https://lists.infradead.org/mailman/listinfo/linux-phy