Re: [PATCH v8 3/6] phy: fsl-imx8mq-usb: add runtime PM support

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

Pre-existing issues:
- [Medium] TOCTOU race in tca_blk_typec_switch_set() and tca_blk_init() cau=
ses hardware orientation desynchronization.
--

--- Patch [3]: [PATCH v8 3/6] phy: fsl-imx8mq-usb: add runtime PM support -=
--
commit 2932b088ad1c6fda6302f9ed3f5778ccb0da73b9
Author: Xu Yang <[email protected]>

phy: fsl-imx8mq-usb: add runtime PM support

This commit adds runtime PM support to ensure the PHY clocks are properly=20
gated when the PHY is not in use, reducing power consumption. Clock
management is shifted from the power_on and power_off callbacks into the
new runtime PM callbacks.

> diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/fre=
escale/phy-fsl-imx8mq-usb.c
> index 3a5788c609e1b..42de2cff4d5f3 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
[ ... ]
> @@ -136,17 +137,15 @@ static int tca_blk_typec_switch_set(struct typec_sw=
itch_dev *sw,
>  {
>  	struct imx8mq_usb_phy *imx_phy =3D typec_switch_get_drvdata(sw);
>  	struct tca_blk *tca =3D imx_phy->tca;
> -	int ret;
> =20
>  	if (tca->orientation =3D=3D orientation)
>  		return 0;

[Severity: Medium]
This is a pre-existing issue, but I noticed a potential race condition here.

Does this lockless equality check risk short-circuiting the orientation
switch update if it races with a concurrent initialization?

For instance, if tca_blk_init() is called concurrently during driver probe
or resume, it evaluates tca->orientation locklessly and passes it by value:

tca_blk_init()
    ...
    tca_blk_orientation_set(tca, tca->orientation);

Could tca_blk_typec_switch_set() return 0 here, returning success to the
Type-C core, while the hardware is simultaneously overwritten with a stale
state by tca_blk_init()? This might cause the hardware orientation to become
desynchronized from the Type-C subsystem's expected state, potentially
misrouting USB 3.0 data lines.

[ ... ]

--=20
Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260731-imx8mp-usb=
[email protected]?part=3D3