Re: [net-next 1/9] net: ethernet: ravb: Remove gPTP control from WoL setup and restore

[sashiko-bot@kernel.org]

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

Pre-existing issues:
- [High] Unchecked return value of ptp_clock_register() leads to a kernel panic in ravb_ptp_stop() on failure.
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commit 4d5ada4dabf46fceeae07f219f72c4daaba09e17
Author: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

net: ethernet: ravb: Remove gPTP control from WoL setup and restore

This commit removes the explicit stopping and starting of the gPTP clock
during Wake-on-LAN (WoL) setup and restore. This is because the ndev is
always closed and re-opened during system suspend and resume, which handles
the clock state automatically.

> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 5f88733094d0f..77c0645a1c4d3 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
[ ... ]
> @@ -3201,9 +3198,6 @@ static int ravb_wol_restore(struct net_device *ndev)
>  	if (error)
>  		return error;
>  
> -	if (priv->info->ccc_gac)
> -		ravb_ptp_init(ndev, priv->pdev);
> -

[Severity: High]
This is a pre-existing issue, but since this patch involves the usage of
ravb_ptp_init() and ravb_ptp_stop(), does ravb_ptp_init() need to check
the return value of ptp_clock_register()?

In drivers/net/ethernet/renesas/ravb_ptp.c:ravb_ptp_init(), the return value
is assigned directly without using IS_ERR():

    priv->ptp.clock = ptp_clock_register(&priv->ptp.info, &pdev->dev);

If ptp_clock_register() fails and returns an error pointer like
ERR_PTR(-ENOMEM), priv->ptp.clock will hold this error pointer instead of
a valid clock or NULL.

Later, when ravb_ptp_stop() is unconditionally called during teardown or
driver removal, it executes:

    ptp_clock_unregister(priv->ptp.clock);

Could this cause a kernel panic when ptp_clock_unregister() dereferences
the error pointer (e.g., when locking the internal mutex via
ptp_vclock_in_use)?

>  	if (info->nc_queues)
>  		napi_enable(&priv->napi[RAVB_NC]);
>  	napi_enable(&priv->napi[RAVB_BE]);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260610102432.3538432-2-niklas.soderlund+renesas@ragnatech.se?part=1