RE: [PATCH v4] net: stmmac: fix 'ethtool -P' return -EBUSY

[Joakim Zhang]

> -----Original Message-----
> From: Hao Chen <chenhaoa@xxxxxxxxxxxxx>
> Sent: 2021年7月19日 17:32
> 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 v4] 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>
> ---
>  .../ethernet/stmicro/stmmac/stmmac_ethtool.c  | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> index d0ce608b81c3..25c44c1ecbd6 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
> @@ -15,6 +15,7 @@
>  #include <linux/phylink.h>
>  #include <linux/net_tstamp.h>
>  #include <asm/io.h>
> +#include <linux/pm_runtime.h>
Please in alphabetical order.


>  #include "stmmac.h"
>  #include "dwmac_dma.h"
> @@ -410,13 +411,22 @@ static void stmmac_ethtool_setmsglevel(struct
> net_device *dev, u32 level)
> 
>  }
> 
> -static int stmmac_check_if_running(struct net_device *dev)
> +static int stmmac_ethtool_begin(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;
>  }

Add error check, like:
ret = pm_runtime_get_sync(priv->device);
if (ret < 0) {
	pm_runtime_put_noidle(priv->device);
	return ret;
}

Best Regards,
Joakim Zhang
> +static void stmmac_ethtool_complete(struct net_device *dev) {
> +	struct stmmac_priv *priv = netdev_priv(dev);
> +
> +	pm_runtime_put(priv->device);
> +}
> +
>  static int stmmac_ethtool_get_regs_len(struct net_device *dev)  {
>  	struct stmmac_priv *priv = netdev_priv(dev); @@ -1073,7 +1083,8 @@
> static int stmmac_set_tunable(struct net_device *dev,  static const struct
> ethtool_ops stmmac_ethtool_ops = {
>  	.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
>  				     ETHTOOL_COALESCE_MAX_FRAMES,
> -	.begin = stmmac_check_if_running,
> +	.begin = stmmac_ethtool_begin,
> +	.complete = stmmac_ethtool_complete,
>  	.get_drvinfo = stmmac_ethtool_getdrvinfo,
>  	.get_msglevel = stmmac_ethtool_getmsglevel,
>  	.set_msglevel = stmmac_ethtool_setmsglevel,
> --
> 2.20.1
> 
>