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 D0C1BC433FE for ; Mon, 21 Mar 2022 17:40:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237003AbiCURlj (ORCPT ); Mon, 21 Mar 2022 13:41:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33504 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349805AbiCURlh (ORCPT ); Mon, 21 Mar 2022 13:41:37 -0400 Received: from mail-qk1-x730.google.com (mail-qk1-x730.google.com [IPv6:2607:f8b0:4864:20::730]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A91860CC4 for ; Mon, 21 Mar 2022 10:40:11 -0700 (PDT) Received: by mail-qk1-x730.google.com with SMTP id 1so12234318qke.1 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=L5ZKSnXPzL/mjBpv1XjoL+qJhVSs3aJ2wuN9YslaODIq649WnECkJLn0ua45Ko1DrS mf1Vbw9XPkGOjz/CmuggaIaWRDd6cZqcIp+GJt2IGgVSPWY8MZTZRLlwj+NQ25trKC5i N0ZaZRmV41ygZKHyQwoyxO2dfW0CW2CbCpD429wMg5bCnK3GKWs1mZ5t39E7byP9H8eg 1WIeALap8Ece6mJaOCKNa8500n/Q0LLgP9il8mbuRY+qe3Q0mgXcb3sy8ZY4A9BTd84v +AXy4isX1Q/4ntyrPHAUmwLZgepvefE+qsFEttZ2OK3DCmeU45YBBYoLosvXUzyMT8mS X52g== X-Gm-Message-State: AOAM531mlwbYXbfywB2MbO59wCsBnmTZ1fZEkdES2DSmQa6IAUKdP/Ja sPvdy84uuo5Y9opEqRrRQaEtC3Vo+zXYsGQIdwGDhA== 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-arm-msm@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 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0FE26C433EF for ; Mon, 21 Mar 2022 17:40:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AD8DC10E429; Mon, 21 Mar 2022 17:40:12 +0000 (UTC) Received: from mail-qk1-x72f.google.com (mail-qk1-x72f.google.com [IPv6:2607:f8b0:4864:20::72f]) by gabe.freedesktop.org (Postfix) with ESMTPS id 83F1F10E318 for ; Mon, 21 Mar 2022 17:40:11 +0000 (UTC) Received: by mail-qk1-x72f.google.com with SMTP id v13so12234167qkv.3 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=JwZUxM8IHQjde8u1MCCzk9KWazwVDP0ZqK77VolcZbcT3eHe/T1Cxf93mrF56vnFe/ b6PB29lyVrIOmfLDTFM1lqlyLiu0SbZ+9R8PcxeoNL68w196rp+Lm6u79Cs1mBgeCcXN MsyjyrEsHfyaIvim1/vxhv3OkH4x+dEARf9lsk+vWWMKt/oHH8SG7T8AcTYmr/ljrpjG uwmuWGy58/nEJc/Us8ewPsgPKWntjFCpEVix2kHJRsZYvXdaCeu3BYu62ccP7Zbg/+44 nRCq1DLKywtkft77tvd0JsGrWZCXkruJKGVXO6cIJNvTGjLTdGSjTWMcGZeXzB7jMLMF R4bQ== X-Gm-Message-State: AOAM530RihTJgcWW/ABo43IBht/jnxH19xj99O3frrqVuOIQUpTeOIPr nRJvXyRMvVYDs/u9YsvaJH4fAEW5jP1cE45C4kmQ8w== 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 Content-Type: text/plain; charset="UTF-8" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: quic_kalyant , "devicetree@vger.kernel.org" , "dianders@chromium.org" , "linux-arm-msm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , quic_vpolimer , Stephen Boyd , "freedreno@lists.freedesktop.org" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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