Re: [PATCH v7 08/27] phy: rockchip: usbdp: Limit DP lane count to muxed lanes

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The target patch introduces a validation check against `udphy->dp_lanes`, but this struct member does not exist at this point in the patch series, causing a fatal build error. Even if it did exist, it is not initialized, leading to permanent validation failure.
--

commit 4d319652ccfe3b1db53193c06a94733191acf3bc
Author: Sebastian Reichel <sebastian.reichel@collabora.com>

phy: rockchip: usbdp: Limit DP lane count to muxed lanes

This commit adds a check to limit the DP lane count to the number of muxed
lanes available on the PHY, preventing the DP controller from requesting
4 lanes when restricted to 2.

Closes: https://lore.kernel.org/linux-phy/20260612165546.98E1F1F000E9@smtp.kernel.org/

> diff --git a/drivers/phy/rockchip/phy-rockchip-usbdp.c b/drivers/phy/rockchip/phy-rockchip-usbdp.c
> index 121dd78d8c161..2324f9050f638 100644
> --- a/drivers/phy/rockchip/phy-rockchip-usbdp.c
> +++ b/drivers/phy/rockchip/phy-rockchip-usbdp.c
> @@ -1132,6 +1132,9 @@ static int rk_udphy_dp_phy_verify_link_rate(struct rk_udphy *udphy,
>  static int rk_udphy_dp_phy_verify_lanes(struct rk_udphy *udphy,
>  					struct phy_configure_opts_dp *dp)
>  {
> +	if (dp->lanes > udphy->dp_lanes)
> +		return -EINVAL;
> +

[Severity: High]
Does this break the build at this point in the patch series?

It appears that the dp_lanes member of struct rk_udphy is not yet declared
or initialized at this point in the tree. This would cause a compilation
failure and break git bisect. Additionally, if the field were present but
uninitialized, it would evaluate to 0 and cause this check to unconditionally
return -EINVAL, breaking DisplayPort configuration.

I understand this is resolved later in the patch series by commit
02003c09070591a7 ("phy: rockchip: usbdp: Support single-lane DP"), which
adds and correctly initializes the dp_lanes struct member. Could the struct
member addition be moved to this commit to ensure the build remains fully
bisectable?

>  	switch (dp->lanes) {
>  	case 1:
>  	case 2:

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260625-rockchip-usbdp-cleanup-v7-0-38eb3cf654fd@collabora.com?part=8