Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1036000AbdD1Nuu (ORCPT ); Fri, 28 Apr 2017 09:50:50 -0400 Received: from relmlor4.renesas.com ([210.160.252.174]:55639 "EHLO relmlie3.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2998153AbdD1Nui (ORCPT ); Fri, 28 Apr 2017 09:50:38 -0400 X-IronPort-AV: E=Sophos;i="5.37,388,1488812400"; d="scan'208";a="242141902" From: Chris Brandt To: Linus Walleij , Jacopo Mondi CC: Geert Uytterhoeven , Laurent Pinchart , Rob Herring , "Mark Rutland" , Russell King , Linux-Renesas , "linux-gpio@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Thread-Topic: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Thread-Index: AQHSvy9EURq5AGyGDkyOQ4Jftj1YPqHaelYAgABQ0YA= Date: Fri, 28 Apr 2017 13:50:32 +0000 Message-ID: References: <1493281194-5200-1-git-send-email-jacopo+renesas@jmondi.org> <1493281194-5200-11-git-send-email-jacopo+renesas@jmondi.org> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: linaro.org; dkim=none (message not signed) header.d=none;linaro.org; dmarc=none action=none header.from=renesas.com; x-originating-ip: [75.60.247.61] x-microsoft-exchange-diagnostics: 1;SG2PR06MB1168;7:Q4418jQRMg8tinw9EZ3aFLEpp4dNkZ+lrYv2n0OcyyQ55S4vxB2+2kcsoTLWd17llUbXGNJc0QJNFrUbeAo6Y7JU80EzcJ3uTKueiJQoZvwY1azQLIEZ9TJShhCWslakb3oTijosktOzlrHdpaKTVzvf1PNJXM7EzYKXMWYUwZstNw3Usnp3U5mlXSZE2xaBdnTwAXZwQ18+1fyKvNtSV+qnbHpWVE+m3qqqXpzyhPRwOhx32rH/5pcnh2AeAsvZdn0YdNmhSZaauAQ+JpVz5xeiuAIyv7zs06lBnE3/s1LNT6G5QkbJjxRMTvE9U4u01btlw04gt2dg6l1Wi4WoqQ==;20:LYxn1jCZGXb5IhS0jYlVjDIN+USpb9QQhJFmvYGHD7HpsyMmdwbLzHxEna7D4PLloLFGBsg4f8BDD/6lBNiIXS6kcWY/BixC2S2yEaOtA+F8tqa8hP5Nb2O/C2xaf81aZo0LPvsUUIHxyLZEPks2+38Nc8bUYTQwUkKXWf0HI9A= x-ms-office365-filtering-correlation-id: 9b7fb6ae-0b9a-4c91-008e-08d48e3d8a1d x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001)(2017030254075)(48565401081)(201703131423075)(201703031133081);SRVR:SG2PR06MB1168; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(17755550239193); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040450)(601004)(2401047)(8121501046)(5005006)(3002001)(93006095)(93001095)(10201501046)(6055026)(6041248)(20161123564025)(20161123555025)(20161123562025)(20161123560025)(201703131423075)(201702281528075)(201703061421075)(6072148);SRVR:SG2PR06MB1168;BCL:0;PCL:0;RULEID:;SRVR:SG2PR06MB1168; x-forefront-prvs: 029174C036 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(39450400003)(39840400002)(39860400002)(39850400002)(39400400002)(39410400002)(24454002)(86362001)(25786009)(2906002)(77096006)(3280700002)(50986999)(76176999)(7416002)(3660700001)(54356999)(33656002)(6246003)(74316002)(7696004)(4326008)(2900100001)(6116002)(102836003)(2950100002)(3846002)(53936002)(189998001)(9686003)(99286003)(54906002)(5660300001)(8936002)(8676002)(55016002)(229853002)(81166006)(38730400002)(6436002)(7736002)(6506006)(122556002)(66066001)(305945005);DIR:OUT;SFP:1102;SCL:1;SRVR:SG2PR06MB1168;H:SG2PR06MB1165.apcprd06.prod.outlook.com;FPR:;SPF:None;MLV:sfv;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-OriginatorOrg: renesas.com X-MS-Exchange-CrossTenant-originalarrivaltime: 28 Apr 2017 13:50:32.5026 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 53d82571-da19-47e4-9cb4-625a166a4a2a X-MS-Exchange-Transport-CrossTenantHeadersStamped: SG2PR06MB1168 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id v3SDp6Yi030374 Content-Length: 1016 Lines: 26 On Friday, April 28, 2017, Linus Walleij wrote: > > Add pin configuration subnode for ETHER ethernet controller. > > > > Signed-off-by: Jacopo Mondi > (...) > > + pins_bidir { > > + pinmux = ;/* P3_3 = > ET_MDIO */ > > + bi-directional; > > + }; > > So I'm against merging this until someone explains what "bi-directional" > actually means, electrically speaking. What happens physically on this > pin? > > I think this just means open drain. > > It is dangerous to merge things we don't understand. > > Surely someone inside Renesas can answer this question. I don't think this has anything to do with open drain because you need it for any pin that the peripheral IP block needs to transmit and receive over the same line, regardless of if it's a SDHI, I2C, Ethernet MDIO, etc... It's more about of allowing the internal IP block signals to get hooked up to the IO pad signals. Chris