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Date:   Mon, 27 Jul 2020 07:29:25 -0700
From:   Richard Cochran <richardcochran@gmail.com>
To:     "Ooi, Joyce" <joyce.ooi@intel.com>
Cc:     Thor Thayer <thor.thayer@linux.intel.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Dalon Westergreen <dalon.westergreen@linux.intel.com>,
        Tan Ley Foon <ley.foon.tan@intel.com>,
        See Chin Liang <chin.liang.see@intel.com>,
        Dinh Nguyen <dinh.nguyen@intel.com>,
        Dalon Westergreen <dalon.westergreen@intel.com>
Subject: Re: [PATCH v5 08/10] net: eth: altera: add support for ptp and
 timestamping
Message-ID: <20200727142925.GB16836@hoboy>
References: <20200727092157.115937-1-joyce.ooi@intel.com>
 <20200727092157.115937-9-joyce.ooi@intel.com>
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On Mon, Jul 27, 2020 at 05:21:55PM +0800, Ooi, Joyce wrote:

> +/* ioctl to configure timestamping */
> +static int tse_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
> +{
> +	struct altera_tse_private *priv = netdev_priv(dev);
> +	struct hwtstamp_config config;
> +
> +	if (!netif_running(dev))
> +		return -EINVAL;
> +
> +	if (!priv->has_ptp) {
> +		netdev_alert(priv->dev, "Timestamping not supported");
> +		return -EOPNOTSUPP;
> +	}

The user might well have a PHY that supports time stamping.  The code
must pass the ioctl through to the PHY even when !priv->has_ptp.

> +
> +	if (!dev->phydev)
> +		return -EINVAL;
> +
> +	if (!phy_has_hwtstamp(dev->phydev)) {
> +		if (cmd == SIOCSHWTSTAMP) {
> +			if (copy_from_user(&config, ifr->ifr_data,
> +					   sizeof(struct hwtstamp_config)))
> +				return -EFAULT;
> +
> +			if (config.flags)
> +				return -EINVAL;
> +
> +			switch (config.tx_type) {
> +			case HWTSTAMP_TX_OFF:
> +				priv->hwts_tx_en = 0;
> +				break;
> +			case HWTSTAMP_TX_ON:
> +				priv->hwts_tx_en = 1;
> +				break;
> +			default:
> +				return -ERANGE;
> +			}
> +
> +			switch (config.rx_filter) {
> +			case HWTSTAMP_FILTER_NONE:
> +				priv->hwts_rx_en = 0;
> +				config.rx_filter = HWTSTAMP_FILTER_NONE;
> +				break;
> +			default:
> +				priv->hwts_rx_en = 1;
> +				config.rx_filter = HWTSTAMP_FILTER_ALL;
> +				break;
> +			}
> +
> +			if (copy_to_user(ifr->ifr_data, &config,
> +					 sizeof(struct hwtstamp_config)))
> +				return -EFAULT;
> +			else
> +				return 0;
> +		}
> +
> +		if (cmd == SIOCGHWTSTAMP) {
> +			config.flags = 0;
> +
> +			if (priv->hwts_tx_en)
> +				config.tx_type = HWTSTAMP_TX_ON;
> +			else
> +				config.tx_type = HWTSTAMP_TX_OFF;
> +
> +			if (priv->hwts_rx_en)
> +				config.rx_filter = HWTSTAMP_FILTER_ALL;
> +			else
> +				config.rx_filter = HWTSTAMP_FILTER_NONE;
> +
> +			if (copy_to_user(ifr->ifr_data, &config,
> +					 sizeof(struct hwtstamp_config)))
> +				return -EFAULT;
> +			else
> +				return 0;
> +		}
> +	}
> +
> +	return phy_mii_ioctl(dev->phydev, ifr, cmd);
> +}

Thanks,
Richard