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=-1.7 required=3.0 tests=DKIM_ADSP_ALL,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=unavailable 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 93708C169C4 for ; Mon, 11 Feb 2019 15:54:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DF7321B18 for ; Mon, 11 Feb 2019 15:54:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=plaes.org header.i=@plaes.org header.b="UcWzavtC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731144AbfBKOf4 (ORCPT ); Mon, 11 Feb 2019 09:35:56 -0500 Received: from plaes.org ([188.166.43.21]:45486 "EHLO plaes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731113AbfBKOf4 (ORCPT ); Mon, 11 Feb 2019 09:35:56 -0500 Received: from plaes.org (localhost [127.0.0.1]) by plaes.org (Postfix) with ESMTPSA id C02C9412CA; Mon, 11 Feb 2019 14:35:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=plaes.org; s=mail; t=1549895753; bh=8Gi4omit073u81WaoF9zvkqRCS3LXU7oUSEGO5wyFVg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UcWzavtCei5KDgJWdYUmJqg3iM+kJGgqI6RL1LfSuXi7HxH8x92/YtcE/TFpRV/vd OXTkEpfGw0zTjOOhXn26nTz88366xRfx/duaJqI5JvIA6oDOpPckgIU4P3dDRu3uN4 l9z2yNsJdbOCz1Hrle7EwdowWHV6rNEPpa+KU1XNhHWubpo5LKKYZhK7ZPpF4LFvEp dXlObLMkJjG1EudRgdcaFUugj+GukUBJQ8cYeGpYhXF5b8vf7dhXZtywiCn+KupPB5 ku36ilStHzdIwhC5RzuoXiDBk0fiXEaiuIYZA3G36e8i53XSBp8x9scneTReEAt+ta IP0ydVUHZEYrA== Date: Mon, 11 Feb 2019 14:35:52 +0000 From: Priit Laes To: Maxime Ripard Cc: Chen-Yu Tsai , Michael Turquette , Stephen Boyd , linux-arm-kernel , linux-clk , linux-kernel , Jernej Skrabec Subject: Re: [RFC PATCH] clk: sunxi-ng: sun4i: Use CLK_SET_RATE_PARENT for mmc2 clock Message-ID: <20190211143552.2uqx6yy53dyv5lbl@plaes.org> References: <20190202155209.31617-1-plaes@plaes.org> <20190205094529.t7je4ozzu2b4ornc@flea> <20190206092000.f46nsn4fw2n4crub@flea> <20190206100309.dhkm2l73qzkwgjzg@plaes.org> <20190206155227.wbkzvsdgykir4wn5@flea> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190206155227.wbkzvsdgykir4wn5@flea> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On Wed, Feb 06, 2019 at 04:52:27PM +0100, Maxime Ripard wrote: > Hi, > > On Wed, Feb 06, 2019 at 10:03:09AM +0000, Priit Laes wrote: > > > > I'm concerned for other users of the PLL-PERIPH clock. AFAIK > > > > all of them, except the HRTIMER, expect the clock rate to stay > > > > the same and not change underneath them. And SATA expects it to > > > > be at 600 MHz, as the datasheet says. And while it may not directly > > > > apply to the LIME2, eMMC on newer SoCs / boards run at the slightly > > > > reduced rate of 50 MHz just fine. > > > > > > > > In the commit in question, clocks without CLK_SET_RATE_PARENT > > > > should be using the old code (now in the if conditional block), > > > > i.e. the behavior should not have changed. > > > > > > > > I don't think this actually "fixes" whatever bug was introduced, > > > > but only papers over the issue, and possible introduces further > > > > issues for other users. > > > > > > You're right, I've overlooked that it was pll-periph being > > > affected. I've dropped it for now. > > > > Any ideas what could be done. I currently have no time to debug it, > > but it affects existing systems. > > I can't find what would change with that commit either if the flag > isn't set, so looking at the register state before and after that > commit would help I guess? Register dump without the patch: $ busybox devmem 0x01c20090 0x0250030E pll-ddr-base 2 2 0 768000000 0 0 50000 pll-ddr-other 1 1 0 768000000 0 0 50000 mmc2 3 3 0 51200000 0 0 50000 Register dump with patch applied, booted from mmc0 and after mounting emmc: $ busybox devmem 0x01c20090 0x8140020B pll-periph-base 3 3 0 1200000000 0 0 50000 pll-periph 6 6 0 600000000 0 0 50000 mmc2 3 3 0 50000000 0 0 50000 > > Maxime > > -- > Maxime Ripard, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com