From patchwork Thu Oct 31 09:29:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 13857747 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6DA4FE68960 for ; Thu, 31 Oct 2024 09:32:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=U9LkV+rq/H9we/2rNOGIF0m4NvoRYUMVY6IOkk0Hvn0=; b=SqqrBgYs9BZMBX1YHdNrE+DzgI T4reeVp7HeMm6q5oWDJSEhjbgqSQswTc9anBfgvB1w6df28ZJB6+VLMvwTSmPCeDvT7Hfxn3Ef7Pm UeHu4CF5EMGPw131tovThStw9ImyIUeVkcby1EJNKD54vP5oFrzLibrv3jcPEzuRC8HC3TeDRGV6J GfUjiRWn3O48BSZf9QoPtnOBHNVJYiPaKS04hcP3IVzd0fU/rQ9HL2i+kTpl+1RvEtkkQ8egsUVnK wwYatOBEOrZq1d/w4s8mmRmW6jc9tljop6GH4bAhG5hGcqLOjaIE6fUrGEcux4T6pSVcqC/UXturc uVx3WXvA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t6RXM-000000035lB-1mZU; Thu, 31 Oct 2024 09:32:16 +0000 Received: from baptiste.telenet-ops.be ([2a02:1800:120:4::f00:13]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t6RVh-000000035U2-3JZp for linux-arm-kernel@lists.infradead.org; Thu, 31 Oct 2024 09:30:35 +0000 Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed80:ceb8:3fda:3601:820f]) by baptiste.telenet-ops.be with cmsmtp id WxWS2D0094BbGPD01xWSpB; Thu, 31 Oct 2024 10:30:26 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtp (Exim 4.95) (envelope-from ) id 1t6RVG-0061eS-VM; Thu, 31 Oct 2024 10:30:25 +0100 Received: from geert by rox.of.borg with local (Exim 4.95) (envelope-from ) id 1t6RV3-006hZj-2d; Thu, 31 Oct 2024 10:29:53 +0100 From: Geert Uytterhoeven To: Tony Lindgren , Kevin Hilman , Roger Quadros , Robert Nelson , Colin Foster Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Geert Uytterhoeven Subject: [PATCH] ARM: dts: am335x-bone-common: Increase MDIO reset deassert delay to 50ms Date: Thu, 31 Oct 2024 10:29:51 +0100 Message-Id: <9002a58daa1b2983f39815b748ee9d2f8dcc4829.1730366936.git.geert+renesas@glider.be> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241031_023033_989841_7591F8BC X-CRM114-Status: GOOD ( 12.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Commit b9bf5612610aa7e3 ("ARM: dts: am335x-bone-common: Increase MDIO reset deassert time") already increased the MDIO reset deassert delay from 6.5 to 13 ms, but this may still cause Ethernet PHY probe failures: SMSC LAN8710/LAN8720 4a101000.mdio:00: probe with driver SMSC LAN8710/LAN8720 failed with error -5 On BeagleBone Black Rev. C3, ETH_RESETn is controlled by an open-drain AND gate. It is pulled high by a 10K resistor, and has a 4.7µF capacitor to ground, giving an RC time constant of 47ms. As it takes 0.7RC to charge the capacitor above the threshold voltage of a CMOS input (VDD/2), the delay should be at least 33ms. Considering the typical tolerance of 20% on capacitors, 40ms would be safer. Add an additional safety margin and settle for 50ms. Signed-off-by: Geert Uytterhoeven Reviewed-by: Roger Quadros Reviewed-by: Kevin Hilman Tested-by: Kevin Hilman --- arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi b/arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi index a0fb431aec8411d8..212d7f867f8786af 100644 --- a/arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi +++ b/arch/arm/boot/dts/ti/omap/am335x-bone-common.dtsi @@ -409,7 +409,7 @@ ethphy0: ethernet-phy@0 { /* Support GPIO reset on revision C3 boards */ reset-gpios = <&gpio1 8 GPIO_ACTIVE_LOW>; reset-assert-us = <300>; - reset-deassert-us = <13000>; + reset-deassert-us = <50000>; }; };