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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_ADSP_ALL, DKIM_SIGNED,DKIM_VALID,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 719DDC3A5A3 for ; Tue, 27 Aug 2019 13:49:21 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 4567F2173E for ; Tue, 27 Aug 2019 13:49:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="i4PvEhyn"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=megous.com header.i=@megous.com header.b="sInfPNmy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4567F2173E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=megous.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=TttFs5Wb/HklBvKTxcgCLnG7tdEuwTQIB5dc/3ReUhU=; b=i4PvEhynkDR/QF FzZ/70VP3GM/0cxjRs4FhrpTcRmm16+QWa2l8XUQlGGDh2CC0KwZU29+KPXREAB8Hz7aG0qx/xP+5 mEZCrbcWAYYIQw31ZGIOnFeOuGsYzhZiZG4g9aiqran7aoSGcXKlxs8EYo/AnnDJFLtflErtNiYw4 F/q4jOdkXqQ2lp9hM5ULwab6101PkYD2lx7ekUJC0JFKnYCGeyDZF+ZB1hjvCuJNE8yAHHnq6RNiM Ss9Pf6gyGAPmUN+oD+tEIqSVp5ZzrkxTVruDv8cZFxmXqjAvwBgOkHPdhQg6OPq8o0CvJ61TURU/z LfoRAoivAPuO5Hu4csUw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i2bqa-0004iy-N4; Tue, 27 Aug 2019 13:49:20 +0000 Received: from vps.xff.cz ([195.181.215.36]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i2bpT-0004Dy-88 for linux-arm-kernel@lists.infradead.org; Tue, 27 Aug 2019 13:48:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megous.com; s=mail; t=1566913686; bh=gUkiaA2UIAfdqLZqpz83L/LrKryHgSOsMfxD9p5JB0g=; h=Date:From:To:Cc:Subject:References:X-My-GPG-KeyId:From; b=sInfPNmyAp81M2iQxMQJOE28y/Ho0Y8utaCVwSOeVpnZ9lPQ14QaOa5uVI27fnTN5 cCVcd9Dz3wvLkYxGyn4l8FmgikPs9k0c3XzJpOfsBok90o5FCZbg8rkUf8Xk3wQBy7 q+cBxetxCsNjEQRtNK/YhpgyExf19CKbEms/5oIM= Date: Tue, 27 Aug 2019 15:48:06 +0200 From: =?utf-8?Q?Ond=C5=99ej?= Jirman To: Maxime Ripard Subject: Re: [PATCH] arm64: dts: allwinner: a64: pine64-plus: Add PHY regulator delay Message-ID: <20190827134806.5l7dxyvzjrvabh7o@core.my.home> Mail-Followup-To: Maxime Ripard , Jernej Skrabec , wens@csie.org, robh+dt@kernel.org, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com References: <20190825130336.14154-1-jernej.skrabec@siol.net> <20190827133443.fdxl5wjmgkerc3uh@flea> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190827133443.fdxl5wjmgkerc3uh@flea> X-My-GPG-KeyId: EBFBDDE11FB918D44D1F56C1F9F0A873BE9777ED X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190827_064811_618530_88328A9F X-CRM114-Status: GOOD ( 13.35 ) 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: mark.rutland@arm.com, devicetree@vger.kernel.org, Jernej Skrabec , linux-sunxi@googlegroups.com, linux-kernel@vger.kernel.org, wens@csie.org, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On Tue, Aug 27, 2019 at 03:34:43PM +0200, Maxime Ripard wrote: > On Sun, Aug 25, 2019 at 03:03:36PM +0200, Jernej Skrabec wrote: > > Depending on kernel and bootloader configuration, it's possible that > > Realtek ethernet PHY isn't powered on properly. It needs some time > > before it can be used. > > > > Fix that by adding 100ms ramp delay to regulator responsible for > > powering PHY. > > > > Fixes: 94dcfdc77fc5 ("arm64: allwinner: pine64-plus: Enable dwmac-sun8i") > > Suggested-by: Ondrej Jirman > > Signed-off-by: Jernej Skrabec > > How was that delay found? I suggested it. There's no delay in the dwmac-sun8i driver, so after enabling the phy power, it will start accessing it over MDIO right away, which is not good. I suggested the value based on post-reset delay in the PHY's datasheet (30ms). Multiplied ~3x (if I remember correctly) to get some safety margin. Chip has more to do then after the HW reset, and regulator also needs some time to ramp-up. regards, o. > It should at least have a comment explaining why it's there. > > Thanks! > Maxime > > -- > Maxime Ripard, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel