From mboxrd@z Thu Jan 1 00:00:00 1970 From: Markus Niebel Subject: Re: [RESEND PATCH v2 1/1] net: phy: micrel: add 125MHz reference clock workaround Date: Tue, 15 May 2018 20:11:13 +0200 Message-ID: <1526407873.17254.8.camel@tqsc.de> References: <20180515081856.23322-1-m.felsch@pengutronix.de> <20180515081856.23322-2-m.felsch@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180515081856.23322-2-m.felsch@pengutronix.de> Sender: netdev-owner@vger.kernel.org To: Marco Felsch , robh+dt@kernel.org, mark.rutland@arm.com, andrew@lunn.ch, f.fainelli@gmail.com Cc: netdev@vger.kernel.org, devicetree@vger.kernel.org, kernel@pengutronix.de, Markus.Niebel@tq-group.com List-Id: devicetree@vger.kernel.org Am Dienstag, den 15.05.2018, 10:18 +0200 schrieb Marco Felsch: > From: Markus Niebel > > The micrel KSZ9031 phy has a optional clock pin (CLK125_NDO) which can be > used as reference clock for the MAC unit. The clock signal must meet the > RGMII requirements to ensure the correct data transmission between the > MAC and the PHY. The KSZ9031 phy does not fulfill the duty cycle > requirement if the phy is configured as slave. For a complete > describtion look at the errata sheets: DS80000691D or DS80000692D. > > The errata sheet recommends to force the phy into master mode whenever > there is a 1000Base-T link-up as work around. Only set the > "micrel,force-master" property if you use the phy reference clock provided > by CLK125_NDO pin as MAC reference clock in your application. > > Attenation, this workaround is only usable if the link partner can > be configured to slave mode for 1000Base-T. > Thank you for documenting and bringing it mainline, should be clear enough what the modification is meant for. Markus