Re: [PATCH v11 17/36] phy: rockchip: usbdp: Drop DP HPD handling

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The typec_mux_set callback explicitly ignores base Type-C states (TYPEC_STATE_SAFE and TYPEC_STATE_USB), preventing the PHY from reverting to standard USB mode when exiting DP AltMode.
--

--- Patch [17]: [PATCH v11 17/36] phy: rockchip: usbdp: Drop DP HPD handling ---
commit 4dd3353e7fa8e127b70281da8c2e85645bfbef65
Author: Sebastian Reichel <sebastian.reichel@collabora.com>

phy: rockchip: usbdp: Drop DP HPD handling

This commit removes the HPD (Hot Plug Detect) handling logic from the
USBDP PHY driver, delegating it to the displayport controller. It also
simplifies the typec_mux_set callback by dropping AltMode specific event
handling and adding an early return for non-DP events.

> diff --git a/drivers/phy/rockchip/phy-rockchip-usbdp.c b/drivers/phy/rockchip/phy-rockchip-usbdp.c
> index 8ac6a83b0b2a9..24108816e3b95 100644
> --- a/drivers/phy/rockchip/phy-rockchip-usbdp.c
> +++ b/drivers/phy/rockchip/phy-rockchip-usbdp.c

[ ... ]

> @@ -1309,6 +1267,14 @@ static int rk_udphy_typec_mux_set(struct typec_mux_dev *mux,
>  	struct rk_udphy *udphy = typec_mux_get_drvdata(mux);
>  	u8 mode;
>  
> +	/*
> +	 * Ignore mux events not involving DP AltMode, because
> +	 * the mode field is being reused, e.g. state->mode == 4
> +	 * could be either TYPEC_MODE_USB4 or TYPEC_DP_STATE_C.
> +	 */
> +	if (!state->alt || state->alt->svid != USB_TYPEC_DP_SID)
> +		return 0;

[Severity: High]
This isn't a bug introduced by this patch, but does this early return
prevent the PHY from reverting to standard USB mode when exiting DP AltMode?

When a user dynamically disables DP AltMode or the DP sink disconnects,
the Type-C core invokes typec_mux_set with state->mode = TYPEC_STATE_SAFE
and state->alt = NULL.

If this returns 0 immediately because state->alt is NULL, udphy->mode
remains stuck at UDPHY_MODE_DP. Later, rk_udphy_usb3_phy_init() will see
that the USB mode is not set (!(udphy->mode & UDPHY_MODE_USB)) and
will actively disable the USB3 port.

Should this condition be adjusted to only filter modal states, perhaps by
checking if state->mode >= TYPEC_STATE_MODAL before filtering based on
the AltMode SVID?

> +
>  	mutex_lock(&udphy->mutex);

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260709-rockchip-usbdp-cleanup-v11-0-a149ac60f76c@collabora.com?part=17