RE: [PATCH v2] net: stmmac: fix 'ethtool -P' return -EBUSY

[Joakim Zhang]

> -----Original Message-----
> From: Hao Chen <chenhaoa@xxxxxxxxxxxxx>
> Sent: 2021年7月19日 15:44
> To: peppe.cavallaro@xxxxxx
> Cc: alexandre.torgue@xxxxxxxxxxx; joabreu@xxxxxxxxxxxx;
> davem@xxxxxxxxxxxxx; kuba@xxxxxxxxxx; mcoquelin.stm32@xxxxxxxxx;
> linux@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx;
> linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> Hao Chen <chenhaoa@xxxxxxxxxxxxx>
> Subject: [PATCH v2] net: stmmac: fix 'ethtool -P' return -EBUSY
> 
> The permanent mac address should be available for query when the device is
> not up.
> NetworkManager, the system network daemon, uses 'ethtool -P' to obtain the
> permanent address after the kernel start. When the network device is not up,
> it will return the device busy error with 'ethtool -P'. At that time, it is unable to
> access the Internet through the permanent address by NetworkManager.
> I think that the '.begin' is not used to check if the device is up.
> 
> Signed-off-by: Hao Chen <chenhaoa@xxxxxxxxxxxxx>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> index d0ce608b81c3..7ccb0d738a1c 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> @@ -412,8 +412,10 @@ static void stmmac_ethtool_setmsglevel(struct
> net_device *dev, u32 level)
> 
>  static int stmmac_check_if_running(struct net_device *dev)  {
> -	if (!netif_running(dev))
> -		return -EBUSY;
> +	struct stmmac_priv *priv = netdev_priv(dev);
> +
> +	pm_runtime_get_sync(priv->device);
> +
>  	return 0;
>  }

After this code change, clocks always enabled even the NIC is not up, it's not good.
Should implement .complete() to disable clocks after the info you got?

Best Regards,
Joakim Zhang
> 
> --
> 2.20.1
> 
>