From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 810C6C83008 for ; Tue, 28 Apr 2020 15:28:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4CBB5206E2 for ; Tue, 28 Apr 2020 15:28:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728312AbgD1P2n (ORCPT ); Tue, 28 Apr 2020 11:28:43 -0400 Received: from mail-ot1-f68.google.com ([209.85.210.68]:36947 "EHLO mail-ot1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727917AbgD1P2m (ORCPT ); Tue, 28 Apr 2020 11:28:42 -0400 Received: by mail-ot1-f68.google.com with SMTP id z17so33346334oto.4; Tue, 28 Apr 2020 08:28:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MW/OWSJ7jnlgJeVyEXGr+UHRHBwvDLhnEj4Gw0Faysc=; b=Nf+fnM+pZcFGWPCTcaEKC4Oz4f5HYkfJfGADgAlBXwMl8bmHeHQaAYxdmVOoYRklDi 8lqyQHyNEXUnm1ZNKULaf4km7cvynqmmdc1E70cKhB00Vewt/MneVXnFqatRJUQaageP RR+aDoQwdMpq9Ic5fbyp6vXFaM4glH3IuUIDFLrQKGuY/f/pSKdB9cqox3CyVacx/vX7 kXfeaeJ4f+37XPKeqDukP/I0Syt/nFmcgzunZIwJ3JFFklaH7aw2PvPbGV/dM6fgcHt1 ZbaOVTGsotKeM6lfnqZ287BX325KfCXFEtndqYBXeIdJT3Hd8B7sMAdD1EWXWfCrGnYw 5ZSg== X-Gm-Message-State: AGi0Pua1GdWcdwFRRQo0PW+5RQPArB3I4c5EvEhenQ0lO7tAeLi2NQQj 6gXzO1hS5rvi4TXO3ivkZnOlhgu/6H+xC8tlx7mWlW7d X-Google-Smtp-Source: APiQypLMHJyVIXfFFO2xNpPTu7dzQmo3gqEMYjKRlGRvQ7k6o1mLs/72dhZWPi5STyFqrrxlJOrh3hq9svuLM+e9K0c= X-Received: by 2002:a9d:564:: with SMTP id 91mr23004838otw.250.1588087721620; Tue, 28 Apr 2020 08:28:41 -0700 (PDT) MIME-Version: 1.0 References: <20200422072137.8517-1-o.rempel@pengutronix.de> In-Reply-To: <20200422072137.8517-1-o.rempel@pengutronix.de> From: Geert Uytterhoeven Date: Tue, 28 Apr 2020 17:28:30 +0200 Message-ID: Subject: Re: [PATCH net-next v3] net: phy: micrel: add phy-mode support for the KSZ9031 PHY To: Oleksij Rempel Cc: Andrew Lunn , Florian Fainelli , Heiner Kallweit , David Jander , "David S. Miller" , Sascha Hauer , Linux Kernel Mailing List , netdev , Philippe Schenker , Russell King , Sergei Shtylyov , Linux-Renesas Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Oleksij, On Wed, Apr 22, 2020 at 9:24 AM Oleksij Rempel wrote: > Add support for following phy-modes: rgmii, rgmii-id, rgmii-txid, rgmii-rxid. > > This PHY has an internal RX delay of 1.2ns and no delay for TX. > > The pad skew registers allow to set the total TX delay to max 1.38ns and > the total RX delay to max of 2.58ns (configurable 1.38ns + build in > 1.2ns) and a minimal delay of 0ns. > > According to the RGMII v1.3 specification the delay provided by PCB traces > should be between 1.5ns and 2.0ns. The RGMII v2.0 allows to provide this > delay by MAC or PHY. So, we configure this PHY to the best values we can > get by this HW: TX delay to 1.38ns (max supported value) and RX delay to > 1.80ns (best calculated delay) > > The phy-modes can still be fine tuned/overwritten by *-skew-ps > device tree properties described in: > Documentation/devicetree/bindings/net/micrel-ksz90x1.txt > > Signed-off-by: Oleksij Rempel This is now commit bcf3440c6dd78bfe ("net: phy: micrel: add phy-mode support for the KSZ9031 PHY") in net-next/master. > --- a/drivers/net/phy/micrel.c > +++ b/drivers/net/phy/micrel.c > @@ -597,21 +703,33 @@ static int ksz9031_config_init(struct phy_device *phydev) > } while (!of_node && dev_walker); > > if (of_node) { > + bool update = false; > + > + if (phy_interface_is_rgmii(phydev)) { > + result = ksz9031_config_rgmii_delay(phydev); > + if (result < 0) > + return result; > + } > + > ksz9031_of_load_skew_values(phydev, of_node, > MII_KSZ9031RN_CLK_PAD_SKEW, 5, > - clk_skews, 2); > + clk_skews, 2, &update); > > ksz9031_of_load_skew_values(phydev, of_node, > MII_KSZ9031RN_CONTROL_PAD_SKEW, 4, > - control_skews, 2); > + control_skews, 2, &update); > > ksz9031_of_load_skew_values(phydev, of_node, > MII_KSZ9031RN_RX_DATA_PAD_SKEW, 4, > - rx_data_skews, 4); > + rx_data_skews, 4, &update); > > ksz9031_of_load_skew_values(phydev, of_node, > MII_KSZ9031RN_TX_DATA_PAD_SKEW, 4, > - tx_data_skews, 4); > + tx_data_skews, 4, &update); > + > + if (update && phydev->interface != PHY_INTERFACE_MODE_RGMII) > + phydev_warn(phydev, > + "*-skew-ps values should be used only with phy-mode = \"rgmii\"\n"); This triggers on Renesas Salvator-X(S): Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: *-skew-ps values should be used only with phy-mode = "rgmii" which uses: phy-mode = "rgmii-txid"; and: rxc-skew-ps = <1500>; If I understand Documentation/devicetree/bindings/net/ethernet-controller.yaml correctly: # RX and TX delays are added by the MAC when required - rgmii i.e. any *-skew-ps can be specified. # RGMII with internal RX and TX delays provided by the PHY, # the MAC should not add the RX or TX delays in this case - rgmii-id i.e. *-skew-ps must not be specified. # RGMII with internal RX delay provided by the PHY, the MAC # should not add an RX delay in this case - rgmii-rxid i.e. it's still OK to specify tx*-skew-ps values here... # RGMII with internal TX delay provided by the PHY, the MAC # should not add an TX delay in this case - rgmii-txid ... and rx*-skew-ps values here? Is my understanding correct, and should the check be updated to take into account rxid and txid? BTW, the example in Documentation/devicetree/bindings/net/micrel-ksz90x1.txt still specifies *-skew-ps values with phy-mode = "rgmii-id", so I think that should be updated, too. Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds