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 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 E70BAE68974 for ; Thu, 31 Oct 2024 10:47:53 +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:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=kzAbhMEAZUfyoIVXCjByodeIayg7CrWmA3iwH6kSxRM=; b=fXPPkZuZ6c0vx+o+8hHQXuk7WV gltVnY8EEwjCpYr3SHT8coi4mncab3ACcWm72M9EftQLuQg52xr2KzhIWPZN2DaiTBx2h1ICFeiKy tEiChIkZiI5UbwW2iXuWcduevWxxxJnZHg90BpembMfO2Gvk9cy2aJLDnIQlAGg98of8KJH8QXwwn CNfWy/GUOTwpoA39AdDb9LANJ8btLXWYPIUgnblAkCfN/gRxqFzKMxCohyKfChj5rlf/30rZOFHaH a5sGk5odZ5jnKPFU1NBTQUUKnIIHAuafsYZ6bbcNW2H7vPoCahTWxF6Q6SnHUIDzhkucCnYQlHwH6 S+sREKug==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t6SiN-00000003Ipz-3kQ4; Thu, 31 Oct 2024 10:47:43 +0000 Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t6SfH-00000003IBZ-2gSr for linux-arm-kernel@lists.infradead.org; Thu, 31 Oct 2024 10:44:32 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 1FB98A43DA3; Thu, 31 Oct 2024 10:42:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4667C4CED2; Thu, 31 Oct 2024 10:44:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730371470; bh=6CrcuhJVpVyzZYHnkIztljkwHxS2uMuZoIvXqVnHZpE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=F8k8MLWVVB2n8i2EG2GeD1q+KWJwfLHhbG0e11wMe08iNRpuDg7SqA2SmaHnsfytc Y0/G0ulePUpwG12ZAV2lBwUnzzBBq1QMPcOIr+FXxs22uwSWVh8jy1uNrbe6Cp26qj d6iBikK07CNDrAr5YFGkTvx2S1Nn2q6UutnkBw2THlEGzlys4as0FlRXXtePdg7h2X keQ8lP7E2ScoAtDCmUtp7aH0nZnv9xbbVoal4QXMfW0V/aGqfC2KBmlz7LYxJUCkOk OBWxcKVI/r0Bd6bc+EECIQg+BwariS53hciZ5HxN34pTH+TYPG6S1DwemPPrCixx7g wBovvT29LEr2w== Message-ID: Date: Thu, 31 Oct 2024 12:44:26 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ARM: dts: am335x-bone-common: Increase MDIO reset deassert delay to 50ms To: Geert Uytterhoeven , Tony Lindgren , Kevin Hilman , Robert Nelson , Colin Foster Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <9002a58daa1b2983f39815b748ee9d2f8dcc4829.1730366936.git.geert+renesas@glider.be> Content-Language: en-US From: Roger Quadros In-Reply-To: <9002a58daa1b2983f39815b748ee9d2f8dcc4829.1730366936.git.geert+renesas@glider.be> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241031_034431_766550_36CECBAF X-CRM114-Status: UNSURE ( 8.86 ) X-CRM114-Notice: Please train this message. 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 On 31/10/2024 11:29, Geert Uytterhoeven wrote: > 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