Re: [PATCH] net: usb: ax88179_178a: improve reset check

[Arne Fitzenreiter <arne_f@ipfire.org>]

Hello Jose Ignacio,

this patch fix my issues.

Best regards
Arne


Am 2024-06-17 12:28, schrieb Jose Ignacio Tornos Martinez:
> After ecf848eb934b ("net: usb: ax88179_178a: fix link status when link 
> is
> set to down/up") to not reset from usbnet_open after the reset from
> usbnet_probe at initialization stage to speed up this, some issues have
> been reported.
> 
> It seems to happen that if the initialization is slower, and some time
> passes between the probe operation and the open operation, the second 
> reset
> from open is necessary too to have the device working. The reason is 
> that
> if there is no activity with the phy, this is "disconnected".
> 
> In order to improve this, the solution is to detect when the phy is
> "disconnected", and we can use the phy status register for this. So we 
> will
> only reset the device from reset operation in this situation, that is, 
> only
> if necessary.
> 
> The same bahavior is happening when the device is stopped (link set to
> down) and later is restarted (link set to up), so if the phy keeps 
> working
> we only need to enable the mac again, but if enough time passes between 
> the
> device stop and restart, reset is necessary, and we can detect the
> situation checking the phy status register too.
> 
> cc: stable@vger.kernel.org # 6.6+
> Fixes: ecf848eb934b ("net: usb: ax88179_178a: fix link status when link 
> is set to down/up")
> Reported-by: Yongqin Liu <yongqin.liu@linaro.org>
> Reported-by: Antje Miederhöfer <a.miederhoefer@gmx.de>
> Reported-by: Arne Fitzenreiter <arne_f@ipfire.org>
> Tested-by: Yongqin Liu <yongqin.liu@linaro.org>
> Tested-by: Antje Miederhöfer <a.miederhoefer@gmx.de>
> Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
> ---
>  drivers/net/usb/ax88179_178a.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/usb/ax88179_178a.c 
> b/drivers/net/usb/ax88179_178a.c
> index 51c295e1e823..c2fb736f78b2 100644
> --- a/drivers/net/usb/ax88179_178a.c
> +++ b/drivers/net/usb/ax88179_178a.c
> @@ -174,7 +174,6 @@ struct ax88179_data {
>  	u32 wol_supported;
>  	u32 wolopts;
>  	u8 disconnecting;
> -	u8 initialized;
>  };
> 
>  struct ax88179_int_data {
> @@ -1678,12 +1677,21 @@ static int ax88179_reset(struct usbnet *dev)
> 
>  static int ax88179_net_reset(struct usbnet *dev)
>  {
> -	struct ax88179_data *ax179_data = dev->driver_priv;
> +	u16 tmp16;
> 
> -	if (ax179_data->initialized)
> +	ax88179_read_cmd(dev, AX_ACCESS_PHY, AX88179_PHY_ID, GMII_PHY_PHYSR,
> +			 2, &tmp16);
> +	if (tmp16) {
> +		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
> +				 2, 2, &tmp16);
> +		if (!(tmp16 & AX_MEDIUM_RECEIVE_EN)) {
> +			tmp16 |= AX_MEDIUM_RECEIVE_EN;
> +			ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE,
> +					  2, 2, &tmp16);
> +		}
> +	} else {
>  		ax88179_reset(dev);
> -	else
> -		ax179_data->initialized = 1;
> +	}
> 
>  	return 0;
>  }