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=-2.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH, USER_AGENT_MUTT 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 1916CC07E85 for ; Fri, 7 Dec 2018 17:17:02 +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 DD4552082D for ; Fri, 7 Dec 2018 17:17:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Wtsslizo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DD4552082D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=atomide.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=zpLPsI8xkFo0y1FHXD9OgaxpET+Eu19jJV4qOS2ViZg=; b=WtsslizobdFdSR 4/NurETEJXSFAFHgwZNTEzWGs616tpx+vD4IVwlrTm7csnwHoKGKb241y5YY2GCIGeq7qKb0FVPHl TF/4tbCJ7+MVqr1BXtOp2XoybdY7ofnhZ4ecuCUI+ksdSjZx7FmfVIEsBKVwO3p8ewEqE5l/GOxeG Hm19K/d0i3NStkfGfnNyCyzrVLMwz9qINy3IsIrJ9ka/rffC37t1G6K9s9OcdKefgdROB0r5TgVy3 h47ebdJam1niEN8yVD69Tmzih5++yNhzLCzayY8eK0/nKGDGW0Yj93lueQ3+2MF1eOrudFFYvbncW JTwNWabxXq8VNL3bhnpA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gVJkK-0003Ny-Hm; Fri, 07 Dec 2018 17:17:00 +0000 Received: from muru.com ([72.249.23.125]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gVJkG-0003NE-M9 for linux-arm-kernel@lists.infradead.org; Fri, 07 Dec 2018 17:16:58 +0000 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 3887C80C0; Fri, 7 Dec 2018 17:16:48 +0000 (UTC) Date: Fri, 7 Dec 2018 09:16:42 -0800 From: Tony Lindgren To: Russell King - ARM Linux Subject: Re: [PATCH] Fix OMAP4430 SDP Ethernet startup Message-ID: <20181207171642.GR6707@atomide.com> References: <20181207125224.GW6920@n2100.armlinux.org.uk> <8b8e05e6-f8a1-2dfe-0967-27e5303a2a07@ti.com> <20181207135751.GZ6920@n2100.armlinux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181207135751.GZ6920@n2100.armlinux.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181207_091656_762343_204FAC62 X-CRM114-Status: GOOD ( 18.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Ujfalusi , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Santosh Shilimkar 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 * Russell King - ARM Linux [181207 13:58]: > On Fri, Dec 07, 2018 at 03:40:13PM +0200, Peter Ujfalusi wrote: > > Russell, > > > > On 07/12/2018 14.52, Russell King - ARM Linux wrote: > > > It was noticed that unbinding and rebinding the KSZ8851 ethernet > > > resulted in the driver reporting "failed to read device ID" at probe. > > > Probing the reset line with a 'scope while repeatedly attempting to > > > bind the driver in a shell loop revealed that the KSZ8851 RSTN pin is > > > constantly held at zero, meaning the device is held in reset, and > > > does not respond on the SPI bus. > > > > > > Experimentation with the startup delay on the regulator set to 50ms > > > shows that the reset is positively released after 20ms. > > > > > > Schematics for this board are not available, and the traces are buried > > > in the inner layers of the board which makes tracing where the RSTN pin > > > extremely difficult. We can only guess that the RSTN pin is wired to a > > > reset generator chip driven off the ethernet supply, which fits the > > > observed behaviour. > > > > Based on the schematics of the Blaze device (which should be very close > > to SDP4430): > > > > TPS22902YFPR is used as the regulator switch (gpio48 controlled) > > The VOUT is routed to TPS3808G01DBV (SCH Note: Threshold set at 90%. > > Vsense: 0.405V). > > > > According to the TPS3808 data sheet the RESET delay time when Ct is open > > (this is the case in the schema): MIN/TYP/MAX: 12/20/28 ms. > > > > The 20ms you are seeing confirms this setup. > > Thanks for the confirmation and information. The Blaze schematics > are also unavailable afaics. Thanks applying into omap-for-v4.20/fixes with updated notes from Peter for the wiring. Regards, Tony _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel