From: Ahmad Fatoum <a.fatoum@pengutronix.de> To: Philippe Schenker <philippe.schenker@toradex.com>, "o.rempel@pengutronix.de" <o.rempel@pengutronix.de>, "andrew@lunn.ch" <andrew@lunn.ch> Cc: "shawnguo@kernel.org" <shawnguo@kernel.org>, "kernel@pengutronix.de" <kernel@pengutronix.de>, "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>, "festevam@gmail.com" <festevam@gmail.com>, "linux@armlinux.org.uk" <linux@armlinux.org.uk>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-imx@nxp.com" <linux-imx@nxp.com>, "tglx@linutronix.de" <tglx@linutronix.de>, "s.hauer@pengutronix.de" <s.hauer@pengutronix.de>, "allison@lohutok.net" <allison@lohutok.net>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, "kstewart@linuxfoundation.org" <kstewart@linuxfoundation.org> Subject: Re: [PATCH] ARM: mach-imx6q: add ksz9131rn_phy_fixup Date: Fri, 6 Mar 2020 12:14:20 +0100 [thread overview] Message-ID: <f47a46b9-6d6a-e257-4309-7e49852bc88e@pengutronix.de> (raw) In-Reply-To: <4e48d56f184ed56d15d2ae6706fdb29e4c849132.camel@toradex.com> Hello Philippe, On 3/6/20 10:46 AM, Philippe Schenker wrote: > Hi Andrew and Ahmad, thanks for your comments. I totally forgot about > those more specific phy-modes. But just because none of our driver > supports that. Either the i.MX6 fec-driver as well as the micrel.c PHY > driver supports this tags. > What do you guys suggest then how I should implement that skew stuff? I think implementing them in the Micrel driver would make sense. When more specific skews are supplied, these are used. If not, the rgmii_[tx]?id applies the appropriate timings for length matched lines. Device trees matching your use case will then only have to specify rgmii-txid. > The problem is that i.MX6 has an asynchronic skew of -100 to 900ps only > enabling the PHY-delay on TXC and RXC is not in all cases within the > RGMII timing specs. That's why I implemented this 'weird' numbers. I am not too well-versed with this. What's an asynchronic skew? A non-deterministic internal delay..? So, you try to be as accurate as possible, so the skew is within the acceptable margin? Cheers Ahmad > > Philippe > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
WARNING: multiple messages have this Message-ID (diff)
From: Ahmad Fatoum <a.fatoum@pengutronix.de> To: Philippe Schenker <philippe.schenker@toradex.com>, "o.rempel@pengutronix.de" <o.rempel@pengutronix.de>, "andrew@lunn.ch" <andrew@lunn.ch> Cc: "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, "kstewart@linuxfoundation.org" <kstewart@linuxfoundation.org>, "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>, "s.hauer@pengutronix.de" <s.hauer@pengutronix.de>, "linux@armlinux.org.uk" <linux@armlinux.org.uk>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-imx@nxp.com" <linux-imx@nxp.com>, "kernel@pengutronix.de" <kernel@pengutronix.de>, "shawnguo@kernel.org" <shawnguo@kernel.org>, "tglx@linutronix.de" <tglx@linutronix.de>, "festevam@gmail.com" <festevam@gmail.com>, "allison@lohutok.net" <allison@lohutok.net> Subject: Re: [PATCH] ARM: mach-imx6q: add ksz9131rn_phy_fixup Date: Fri, 6 Mar 2020 12:14:20 +0100 [thread overview] Message-ID: <f47a46b9-6d6a-e257-4309-7e49852bc88e@pengutronix.de> (raw) In-Reply-To: <4e48d56f184ed56d15d2ae6706fdb29e4c849132.camel@toradex.com> Hello Philippe, On 3/6/20 10:46 AM, Philippe Schenker wrote: > Hi Andrew and Ahmad, thanks for your comments. I totally forgot about > those more specific phy-modes. But just because none of our driver > supports that. Either the i.MX6 fec-driver as well as the micrel.c PHY > driver supports this tags. > What do you guys suggest then how I should implement that skew stuff? I think implementing them in the Micrel driver would make sense. When more specific skews are supplied, these are used. If not, the rgmii_[tx]?id applies the appropriate timings for length matched lines. Device trees matching your use case will then only have to specify rgmii-txid. > The problem is that i.MX6 has an asynchronic skew of -100 to 900ps only > enabling the PHY-delay on TXC and RXC is not in all cases within the > RGMII timing specs. That's why I implemented this 'weird' numbers. I am not too well-versed with this. What's an asynchronic skew? A non-deterministic internal delay..? So, you try to be as accurate as possible, so the skew is within the acceptable margin? Cheers Ahmad > > Philippe > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-03-06 11:14 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-05 13:49 [PATCH] ARM: mach-imx6q: add ksz9131rn_phy_fixup Philippe Schenker 2020-03-05 13:49 ` Philippe Schenker 2020-03-05 13:53 ` Russell King - ARM Linux admin 2020-03-05 13:53 ` Russell King - ARM Linux admin 2020-03-06 9:57 ` Philippe Schenker 2020-03-06 9:57 ` Philippe Schenker 2020-03-06 10:52 ` Russell King - ARM Linux admin 2020-03-06 10:52 ` Russell King - ARM Linux admin 2020-03-05 14:38 ` Oleksij Rempel 2020-03-05 14:38 ` Oleksij Rempel 2020-03-05 16:51 ` Andrew Lunn 2020-03-05 16:51 ` Andrew Lunn 2020-03-06 7:42 ` Ahmad Fatoum 2020-03-06 7:42 ` Ahmad Fatoum 2020-03-06 9:46 ` Philippe Schenker 2020-03-06 9:46 ` Philippe Schenker 2020-03-06 11:14 ` Ahmad Fatoum [this message] 2020-03-06 11:14 ` Ahmad Fatoum 2020-03-06 12:16 ` Philippe Schenker 2020-03-06 12:16 ` Philippe Schenker 2020-03-06 13:38 ` Andrew Lunn 2020-03-06 13:38 ` Andrew Lunn 2020-03-06 16:30 ` Philippe Schenker 2020-03-06 16:30 ` Philippe Schenker 2020-03-06 9:55 ` Philippe Schenker 2020-03-06 9:55 ` Philippe Schenker 2020-03-06 10:38 ` Oleksij Rempel 2020-03-06 10:38 ` Oleksij Rempel 2020-03-06 12:36 ` Philippe Schenker 2020-03-06 12:36 ` Philippe Schenker
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