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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B1B53C432BE for ; Mon, 30 Aug 2021 13:25:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9223A600CD for ; Mon, 30 Aug 2021 13:25:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236718AbhH3N0E (ORCPT ); Mon, 30 Aug 2021 09:26:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236691AbhH3N0D (ORCPT ); Mon, 30 Aug 2021 09:26:03 -0400 Received: from mail-qk1-x733.google.com (mail-qk1-x733.google.com [IPv6:2607:f8b0:4864:20::733]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0188C061760 for ; Mon, 30 Aug 2021 06:25:09 -0700 (PDT) Received: by mail-qk1-x733.google.com with SMTP id t4so15521996qkb.9 for ; Mon, 30 Aug 2021 06:25:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=exvJuGKtr25W/uSVhVmLJ9dDndSizQ5pyVnZeMKPf6U=; b=mms14newKPS84RVgPulnIhvgz8tMtpuRypQwgTY51AnAijLWncUJabtEiBlVoTN2zW 3La+fBT4bRu5jdAP5UumDBl8kAE6qewY4pjP76Cpn3e5PKWq1Bg+lQK/1HscAXA5Cf9+ KjCXmdXlXxS3A6PFj6UYj7HcfZRe0h1vWv2wXwgQyWUT3iUFsqyERgT1uizU7kvg5RE0 DAwyxjvkDSaViDtIEI6oQX5qjwriesD2pGB0quveq31AmYLAJnpOu67pUioRufojTDnp ta0OajqFszqYnhSHmAIDdU3vuAI7adD0jZihCKzKybnFoqQBTqNREQp+eiqSk0U1g9gW Jb9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=exvJuGKtr25W/uSVhVmLJ9dDndSizQ5pyVnZeMKPf6U=; b=Uwyqg2zmy+YsulwivAHO9LKrfE7BbAqZAmrgHg47cilpjNwUKYjR1fjLet+3tvaejC CzsUd0UQA+syMAIiv/pBQL885+4CUntZA9gZygun+JugUep2RYSoYVCe6TpQEFV+9HXV v1551cv9s2c1c5/wSdygak7uzN1yCMLRepfdHoB9IKE1HNIW7FWlWpWL1HcrBu5qW1C9 /U35M3VdCkoPjzt2dnt+8TrGTR4rrF4T2dqW/YYda0fRIs8X4GlwI5mWARJFnqoMhjU0 fbuaV3nam6aIwwROJjMif3aB7VWWI8e1mo50jhum+1sUiYWijaSs6Ld8uLKU6jsmfcpf uuyQ== X-Gm-Message-State: AOAM5329FBKPOXvUbY4uP0Fxh/f4AygI0XviMiLErKkb7Gqab5XCvPwW T8l/zv3wNcxs39peu70RGhsAhv3VukfJ4t4UlqRf2Q== X-Google-Smtp-Source: ABdhPJyQrSmYGVRpojLW5kEYAkle9dDkeFrhLBy8INWatlvC+AvXupu8xjM/hefniOjkmj7yvU8Hg3Uvuh7N4naBPko= X-Received: by 2002:a05:620a:941:: with SMTP id w1mr21668872qkw.434.1630329908857; Mon, 30 Aug 2021 06:25:08 -0700 (PDT) MIME-Version: 1.0 References: <20210829203027.276143-1-marijn.suijten@somainline.org> <20210829203027.276143-2-marijn.suijten@somainline.org> <17d19b93-dbe5-cc85-f302-b52cd8eeed56@somainline.org> In-Reply-To: <17d19b93-dbe5-cc85-f302-b52cd8eeed56@somainline.org> From: Dmitry Baryshkov Date: Mon, 30 Aug 2021 16:24:58 +0300 Message-ID: Subject: Re: [PATCH 1/3] arm: dts: qcom: apq8064: Use 27MHz PXO clock as DSI PLL reference To: Marijn Suijten Cc: phone-devel@vger.kernel.org, ~postmarketos/upstreaming@lists.sr.ht, AngeloGioacchino Del Regno , Konrad Dybcio , Martin Botka , Jami Kettunen , Pavel Dubrova , Bjorn Andersson , Andy Gross , Rob Herring , "open list:DRM DRIVER FOR MSM ADRENO GPU" , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Mon, 30 Aug 2021 at 11:28, Marijn Suijten wrote: > > Hi Dmitry, > > On 8/30/21 3:18 AM, Dmitry Baryshkov wrote: > > On Sun, 29 Aug 2021 at 23:30, Marijn Suijten > > wrote: > >> > >> The 28NM DSI PLL driver for msm8960 calculates with a 27MHz reference > >> clock and should hence use PXO, not CXO which runs at 19.2MHz. > >> > >> Note that none of the DSI PHY/PLL drivers currently use this "ref" > >> clock; they all rely on (sometimes inexistant) global clock names and > >> usually function normally without a parent clock. This discrepancy will > >> be corrected in a future patch, for which this change needs to be in > >> place first. > >> > >> Cc: Dmitry Baryshkov > >> Signed-off-by: Marijn Suijten > > > > Reviewed-by: Dmitry Baryshkov > > > > Checked the downstream driver, it always uses 27 MHz clock in calculations. > > > Given our concerns for msm8974 not updating DT in parallel with the > kernel (hence the need for a global-name fallback because "ref" is > missing from the DT), should we worry about the same for apq8064? That > is, is there a chance that the kernel but not the firmware is upgraded > leading to the wrong parent clock being used? The msm8960 variant of > the 28nm PLL driver uses parent_rate in a few places and might read > cxo's 19.2MHz erroneously instead of using pxo's 27MHz. Checked the code. It uses .parent_names = "pxo", so changing ref clock should not matter. We'd need to fix ref clocks and after that we can switch parent names to fw_name. > > - Marijn -- With best wishes Dmitry