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=-8.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 63B71C433DB for ; Sun, 27 Dec 2020 16:01:47 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E028A22512 for ; Sun, 27 Dec 2020 16:01:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E028A22512 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=walle.cc Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:To:From: Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JlYHH+VFPg3naZnmWqJfrCmn0m7acxR3IIyph4Q8kUk=; b=PUzOqZPYATHbPSG+A4mf4t6On q5LtRDXBMyyurSVOtZvg8JieiADbhnJnXHIMI/vzkwW79+HqiGoOfe+QEQDlPay9U2AwAHAmON/ca E8SSl7h1F9B/Pp3n+iqszQUErZRiPHj0DNb1r5S5D5YpGbiJSqrU5NdYgq96WZHLiEAUT7JCScvbV aK8+xQz1NqOPyz6lt/IaJfxBHWTuvqMW+ZCWC2yLiAdTjotihpOSBKB6w8GABjz8SA0LJK2msyEhJ zGqVSormjIorOQt+OWcrGoSF/47XM/3HIsQDHXyp5xi1+F47LCiG1qYJCChvgX85uqHpb5aMZxQ5x 5Fwb94X0g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ktYSO-0005yj-BP; Sun, 27 Dec 2020 15:59:44 +0000 Received: from ssl.serverraum.org ([2a01:4f8:151:8464::1:2]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ktYSK-0005yM-O7 for linux-arm-kernel@lists.infradead.org; Sun, 27 Dec 2020 15:59:41 +0000 Received: from ssl.serverraum.org (web.serverraum.org [172.16.0.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 7173A22ED4; Sun, 27 Dec 2020 16:59:39 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1609084779; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OdgmPEKIsU/7PfwCD+NF5raKB6/WnzRPGqLf6aet0Ro=; b=I0zKGciW1k9WqJJVsa4FyjrD9UKosX7ahAma/INMbLsf4stBCpB6GYo9SMjOOjXvbFrbyf q+KkJidpJLfoYpveEDihZynKlpQesWXQN5WXmR0Y7Yw3GvBU5sI69VoZSYe2OvJg7LIOt4 Yqeo8XFq7YFQps/biQRShHpDdwMr1t8= MIME-Version: 1.0 Date: Sun, 27 Dec 2020 16:59:39 +0100 From: Michael Walle To: Russell King - ARM Linux admin Subject: Re: Broken ethernet on SolidRun cubox-i In-Reply-To: <1d79aa88e73b6e0118e570a64026817e@walle.cc> References: <2ae000163aa34b963dd387c824bdc3c9@walle.cc> <20201226123421.GD1551@shell.armlinux.org.uk> <1d79aa88e73b6e0118e570a64026817e@walle.cc> User-Agent: Roundcube Webmail/1.4.9 Message-ID: X-Sender: michael@walle.cc X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201227_105941_072138_263186AD X-CRM114-Status: GOOD ( 14.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Matus Ujhelyi , acmattheis@gmx.net, Christoph Mattheis , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Am 2020-12-27 16:33, schrieb Michael Walle: > Am 2020-12-26 13:34, schrieb Russell King - ARM Linux admin: >> I'd forgotten that there were boards out there with this problem... >> the PHY address configuration is done via the LED_ACT pin, and >> SolidRun >> omitted a pull resistor on it, so it "floats" with the leakage current >> of the LED/pin - resulting in it sometimes appearing at address 0 and >> sometimes at address 4. > > Mh, I've guessed that too, but there must be more to it. The datasheet > says it has an internal weak pull-up. Or Atheros messed up and it > doesn't > reliably work if there is actually an LED attached to it. But then, why > would any other stronger pull-up/down work.. Mhh, nevermind, from the commit log [1]. "The LED_ACT pin on the carrier-one boards had a pull down that forces the phy address to 0x0; where on CuBox-i and the production HummingBoard that pin is connected directly to LED that depending on the pull down strength of the LED it might be sampled as '0' or '1' thus the phy address might appear as either address 0x0 or 0x4." So it actually depends on the forward voltage of the LED and the hi/low thresholds of the AT8035.. nice! Oh and btw. this pin also switches between high and low-active LED output. So the missing pull-down might not only switch the PHY address to 4 but also invert the LED state. -michael [1] https://github.com/SolidRun/u-boot/commit/712be3eef69a2b0205d3b87fb5ab5632e36722d7 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel