Re: [RFC net-next 4/5] net: phy: Add support for IEEE standard test modes

[Florian Fainelli]

On 04/30/2018 04:20 PM, Andrew Lunn wrote:
>> +/* genphy_set_test - Make a PHY enter one of the standard IEEE defined
>> + * test modes
>> + * @phydev: the PHY device instance
>> + * @test: the desired test mode
>> + * @data: test specific data (none)
>> + *
>> + * This function makes the designated @phydev enter the desired standard
>> + * 100BaseT2 or 1000BaseT test mode as defined in IEEE 802.3-2012 section TWO
>> + * and THREE under 32.6.1.2.1 and 40.6.1.1.2 respectively
>> + */
>> +int genphy_set_test(struct phy_device *phydev,
>> +		    struct ethtool_phy_test *test, const u8 *data)
>> +{
>> +	u16 shift, base, bmcr = 0;
>> +	int ret;
>> +
>> +	/* Exit test mode */
>> +	if (test->mode == PHY_STD_TEST_MODE_NORMAL) {
>> +		ret = phy_read(phydev, MII_CTRL1000);
>> +		if (ret < 0)
>> +			return ret;
>> +
>> +		ret &= ~GENMASK(15, 13);
>> +
>> +		return phy_write(phydev, MII_CTRL1000, ret);
>> +	}
> 
> Hi Florain
> 
> I looked at the Marvell SDK for PHYs. It performs a soft reset after
> swapping back to normal mode. I assume the broadcom PHY does not need
> this? But maybe we can add it anyway?

We certainly should reset the PHY, thanks!

> 
>> +
>> +	switch (test->mode) {
>> +	case PHY_STD_TEST_MODE_100BASET2_1:
>> +	case PHY_STD_TEST_MODE_100BASET2_2:
>> +	case PHY_STD_TEST_MODE_100BASET2_3:
>> +		if (!(phydev->supported & PHY_100BT_FEATURES))
>> +			return -EOPNOTSUPP;
>> +
>> +		shift = 14;
>> +		base = test->mode - PHY_STD_TEST_MODE_NORMAL;
>> +		bmcr = BMCR_SPEED100;
>> +		break;
>> +
>> +	case PHY_STD_TEST_MODE_1000BASET_1:
>> +	case PHY_STD_TEST_MODE_1000BASET_2:
>> +	case PHY_STD_TEST_MODE_1000BASET_3:
>> +	case PHY_STD_TEST_MODE_1000BASET_4:
>> +		if (!(phydev->supported & PHY_1000BT_FEATURES))
>> +			return -EOPNOTSUPP;
>> +
>> +		shift = 13;
>> +		base = test->mode - PHY_STD_TEST_MODE_100BASET2_MAX;
>> +		bmcr = BMCR_SPEED1000;
>> +		break;
>> +
>> +	default:
>> +		/* Let an upper driver deal with additional modes it may
>> +		 * support
>> +		 */
>> +		return -EOPNOTSUPP;
>> +	}
>> +
>> +	/* Force speed and duplex */
>> +	ret = phy_write(phydev, MII_BMCR, bmcr | BMCR_FULLDPLX);
>> +	if (ret < 0)
>> +		return ret;
> 
> Should there be something to undo this when returning to normal mode?

Yes, resetting the PHY would perform that.
-- 
Florian