Messages in this thread | | | Date | Sat, 11 Jun 2022 17:23:02 +0200 | From | Marc Kleine-Budde <> | Subject | Re: [PATCH net-next v3 3/3] net: phy: dp83td510: disable cable test support for 1Vpp PHYs |
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On 11.06.2022 17:16:06, Andrew Lunn wrote: > > static int dp83td510_cable_test_start(struct phy_device *phydev) > > { > > - int ret; > > + struct dp83td510_priv *priv = phydev->priv; > > + int ret, cfg = 0; > > + > > + /* Generate 2.4Vpp pulse if HW is allowed to do so */ > > + if (priv->allow_v2_4_mode) { > > + cfg |= DP83TD510E_TDR_TX_TYPE; > > + } else { > > + /* This PHY do not provide usable results with 1Vpp pulse. > > s/do/does > > > > + * Potentially different dp83td510_tdr_init() values are > > + * needed. > > + */ > > + return -EOPNOTSUPP; > > + } > > I don't remember the details for v2.4. Is it possible to change up > from 1v to 2.4v for the duration of the cable test? Is there a danger > to damage the link peer? I guess not, since you need to pass EMC > testing which zaps it with 100Kv or something. So is this more a local > supply issue?
In some industrial areas (e.g. ATEX (explosion protection)) 2.4V is not allowed due to regulations. If the PHY is strapped to 1.0V we assume for now this has a good reason and don't crank up the voltage :)
regards, Marc
-- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | [unhandled content-type:application/pgp-signature] | |