[PATCH] phy: fsl-lynx-28g: propagate PCVT enable errors

[sashiko-bot at kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Hardware and software state desynchronization on PCVT enable failure prevents mode recovery.
--

--- Patch [1]: [PATCH] phy: fsl-lynx-28g: propagate PCVT enable errors ---
commit 6193a7adcb18a183b9462da919d480f3a6949562
Author: surendra <kr494167 at gmail.com>

phy: fsl-lynx-28g: propagate PCVT enable errors

This commit updates lynx_28g_set_mode() to check the return value of
lynx_28g_lane_enable_pcvt(). If an error occurs, the code now propagates
the error and exits before updating the software lane mode tracking.

> diff --git a/drivers/phy/freescale/phy-fsl-lynx-28g.c b/drivers/phy/freescale/phy-fsl-lynx-28g.c
> index 38afcd081a2a7..1fe406adc83cb 100644
> --- a/drivers/phy/freescale/phy-fsl-lynx-28g.c
> +++ b/drivers/phy/freescale/phy-fsl-lynx-28g.c
> @@ -1003,7 +1003,9 @@ static int lynx_28g_set_mode(struct phy *phy, enum phy_mode mode, int submode)
>  
>  	lynx_28g_lane_change_proto_conf(lane, lane_mode);
>  	lynx_28g_lane_remap_pll(lane, lane_mode);
> -	WARN_ON(lynx_28g_lane_enable_pcvt(lane, lane_mode));
> +	err = lynx_28g_lane_enable_pcvt(lane, lane_mode);
> +	if (err)
> +		goto out;

[Severity: Medium]
Does this new error path leave the software and hardware states
desynchronized?

Prior to this point, the hardware has already been reprogrammed to the
new mode by lynx_28g_lane_change_proto_conf() and
lynx_28g_lane_remap_pll(). If lynx_28g_lane_enable_pcvt() fails and takes
the goto out path, lane->mode remains set to the old mode.

If a caller later attempts to recover by setting the PHY back to the old
mode, lynx_28g_set_mode() will see:

    if (lane_mode == lane->mode)
        return 0;

and short-circuit, preventing the hardware from actually being reverted.

Should the error path either revert the hardware changes or set
lane->mode = LANE_MODE_UNKNOWN to ensure subsequent recovery attempts bypass
the short-circuit check?

>  
>  	lane->mode = lane_mode;
>

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260722033619.10647-1-kr494167@gmail.com?part=1