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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6DA3C4332F for ; Mon, 21 Mar 2022 17:40:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349872AbiCURlk (ORCPT ); Mon, 21 Mar 2022 13:41:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349974AbiCURlh (ORCPT ); Mon, 21 Mar 2022 13:41:37 -0400 Received: from mail-qk1-x734.google.com (mail-qk1-x734.google.com [IPv6:2607:f8b0:4864:20::734]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B02868FAE for ; Mon, 21 Mar 2022 10:40:11 -0700 (PDT) Received: by mail-qk1-x734.google.com with SMTP id b67so12222404qkc.6 for ; Mon, 21 Mar 2022 10:40:11 -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=6W2sIVaPd1wN+ZQSZ4o9j1nJ91W2fIHQV8YHK4mslGI=; b=othMTu8DE+iag13P8/3A86+7Cc/DHfdnjpWo/byQ5ZUfFCsKml6d/b3+j7enHM3E4T p+KQDmhtptyFrPuooWSYmYPJhZWIkHdGt+4vDWYH8iYYuao36WWrhVCMkScMLZUcTZup pbxMXwiUoDBFmduoGs8/S8k0tsoBfeYNIRC0GZYKyyNpLf6jW7ygE9Q4oqBC51xdfcFk 7ttNl5wra931kZmVavvxQVP/9NCHWg77ijwCiHKLw+zmH2XDabD4PX37zubDr18d1FXu LkskplWtgjBIz3OnXb1aT9cH4qssg21daGzI4dNto8OQ0PN0SvwCPVBwRyAb6Xlo3qN2 FbyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6W2sIVaPd1wN+ZQSZ4o9j1nJ91W2fIHQV8YHK4mslGI=; b=ATcfVIhg/3rGCy4HxTgErcjux/o86E6dz15Q9qV6ZdQ+6jaeLlrEpj4dzc+k9KR2bf k1cx9Ef1PTQZaTD5DllZfWeXCLJfwWm4sz9JRNjqhQJRoxKa415YJLbbqy+99sJ7WpQk KuOOL4mWIePJe5M5jAstYM9lL8BHquFjUVkFfLQeGNJs2c72sllcYSvgddIWPKeX++Hh ahd3+NGiFy4Eh2WLfDEM8upyZBSC5pgKQ2Fk2s4Z+HbUHf7Sd2ERQ8xa8qZZAsnVJhx/ 2AZpbK/MyarJyzaBPq7xxRWTp/UIwsGWm34LPFIUsYMwlZ9NSPpjDVs6aMBU2ei2swzE Cvgg== X-Gm-Message-State: AOAM533A9VD5rEdhXTQIj3w0nIe7BQQ2mVESqFMmXybwvHf6HxdocMvE CiRwOrQlYsarKFh31mVol9Pufh+4Ec/dIYv4vWeglA== X-Google-Smtp-Source: ABdhPJzAfOtHcF9CqanODzAbHAfQeaYZMAZcZ9hv0xTWt4ZcE9sSN4BkC8am1z8h+EdgxGiCPhpJswcEmaek2cu2UjE= X-Received: by 2002:a05:620a:2453:b0:67d:9539:495c with SMTP id h19-20020a05620a245300b0067d9539495cmr13674139qkn.30.1647884410564; Mon, 21 Mar 2022 10:40:10 -0700 (PDT) MIME-Version: 1.0 References: <1647269217-14064-1-git-send-email-quic_vpolimer@quicinc.com> <1647269217-14064-2-git-send-email-quic_vpolimer@quicinc.com> In-Reply-To: From: Dmitry Baryshkov Date: Mon, 21 Mar 2022 20:39:59 +0300 Message-ID: Subject: Re: [PATCH v6 1/5] drm/msm/disp/dpu1: set mdp clk to the maximum frequency in opp table during probe To: Vinod Polimera Cc: Stephen Boyd , quic_vpolimer , "devicetree@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "freedreno@lists.freedesktop.org" , "linux-arm-msm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "robdclark@gmail.com" , "dianders@chromium.org" , quic_kalyant Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 21 Mar 2022 at 19:21, Vinod Polimera wrote: > > > > > -----Original Message----- > > From: Stephen Boyd > > Sent: Friday, March 18, 2022 2:41 AM > > To: quic_vpolimer ; > > devicetree@vger.kernel.org; dri-devel@lists.freedesktop.org; > > freedreno@lists.freedesktop.org; linux-arm-msm@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org; robdclark@gmail.com; > > dmitry.baryshkov@linaro.org; dianders@chromium.org; quic_kalyant > > > > Subject: Re: [PATCH v6 1/5] drm/msm/disp/dpu1: set mdp clk to the > > maximum frequency in opp table during probe > > > > WARNING: This email originated from outside of Qualcomm. Please be wary > > of any links or attachments, and do not enable macros. > > > > Quoting Vinod Polimera (2022-03-14 07:46:53) > > > use max clock during probe/bind sequence from the opp table. > > > The clock will be scaled down when framework sends an update. > > > > Capitalize 'use'. > > > > Why is it important to use max frequency during probe/bind? Does not > > setting the clk rate during probe mean that we'll never use the max > > rate? Does it speed things up during probe? > > We need to vote mdp clock during probe/bind so that rails are not set at undetermined state as pointed out by Dmitry. > Since we dont know what will be the rate set in boot loader, it would be ideal to vote at max frequency. > There could be a firmware display programmed in bootloader and we want to transition it to kernel without underflowing. This should be expressed in the commit message. -- With best wishes Dmitry