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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,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 0FD43C433B4 for ; Fri, 23 Apr 2021 16:16:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1B1761354 for ; Fri, 23 Apr 2021 16:16:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231345AbhDWQRb (ORCPT ); Fri, 23 Apr 2021 12:17:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229931AbhDWQRb (ORCPT ); Fri, 23 Apr 2021 12:17:31 -0400 Received: from mail-oi1-x22b.google.com (mail-oi1-x22b.google.com [IPv6:2607:f8b0:4864:20::22b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63712C061574 for ; Fri, 23 Apr 2021 09:16:53 -0700 (PDT) Received: by mail-oi1-x22b.google.com with SMTP id u16so32359074oiu.7 for ; Fri, 23 Apr 2021 09:16:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=nOQQqBqjHuvjx+mAlIOMyHNRurAecyF6kdkwHEmgzso=; b=tLZ9DmttTeYtxODA8GpoGJD3f0Haev5OEYxrAoEu5x/meFKNZ67Xrn6E7wBOaPuifI wNlvV52rK5Y2Mywj2ET9283Zs770zV7NHAs07XT9eYniS6gbUuIJBKyK+2B932VNi9sJ RcIF2vnKJocRtzBB+uIaJGPbfUfBTaB1x5X3zXN7rIb/K/+YrxSv76g7tdXH/v7NLeJF 6y4fg0IDpP2fBw3zv4WDH7ovgaWgetiGIPsn2rRTZs8FHo9D9aURjU9P8iAYP8XWlk3D AZrQ1Qqx6AtlJhlZdjsp8KQVqUuo45eacaZnE1gjIqpoB6PNVJ3i1CYRPq5KNULETOPN QidQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=nOQQqBqjHuvjx+mAlIOMyHNRurAecyF6kdkwHEmgzso=; b=JVZJ+hXXnfcJP6+RVyRx2mP1TsnaFlOUe8dfGll9ceTMgDioYKHb6ErD8JgwYlb8le 7n8rn0ynuSLZGUZfrTAzHE09xRa8Y1cJ1wt20ikK7uJBX77kVyW6To7ak01VwMWjaAYH TnutCQqgZI6/Y/Hx6logyyIrj3xcBw/NhAo3ZFMihPgiqLV2WfpDPnuFxOjne8pePeV9 sPqZN+QZHlKRkH2e8wIClYDi8QNHv1GH+U7quVL9/82fVkmMIUyxZHIcgb6f/CH5Yvso pxxJW2rHPIYFRwtAWdtp4A+Mo0BefQhPE3Wf2DQp8uNLmKcHqSlBDBxlb6zlmyvCqOc5 8XTg== X-Gm-Message-State: AOAM533cKe1Zf10aI/H7DyRr4dQnoljFFY9NbaGEZjIvRNOXiz12ASXQ HszoSePX6vsNxliET6ZjnX2INg== X-Google-Smtp-Source: ABdhPJyxj8Hhn+123lQ/JT8X7RLjGQCf0dKzpHIzSwezdnqt5VNuPgWlbYaErNniQIPS+VIKQ6Nmvg== X-Received: by 2002:aca:db02:: with SMTP id s2mr4534138oig.100.1619194612825; Fri, 23 Apr 2021 09:16:52 -0700 (PDT) Received: from builder.lan (104-57-184-186.lightspeed.austtx.sbcglobal.net. [104.57.184.186]) by smtp.gmail.com with ESMTPSA id h5sm1359874oth.20.2021.04.23.09.16.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Apr 2021 09:16:52 -0700 (PDT) Date: Fri, 23 Apr 2021 11:16:50 -0500 From: Bjorn Andersson To: Douglas Anderson Cc: Andrzej Hajda , Neil Armstrong , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Sam Ravnborg , Wolfram Sang , Stephen Boyd , robdclark@chromium.org, Maarten Lankhorst , Stanislav Lisovskiy , Steev Klimaszewski , linux-arm-msm@vger.kernel.org, Linus W , Daniel Vetter , David Airlie , Thierry Reding , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 27/27] drm/panel: panel-simple: Prepare/unprepare are refcounted, not forced Message-ID: References: <20210416223950.3586967-1-dianders@chromium.org> <20210416153909.v4.27.I502f2a92ddd36c3d28d014dd75e170c2d405a0a5@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210416153909.v4.27.I502f2a92ddd36c3d28d014dd75e170c2d405a0a5@changeid> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Fri 16 Apr 17:39 CDT 2021, Douglas Anderson wrote: > Historically simple-panel had code to make sure that if prepare() was > called on an already-prepared panel that it was a no-op. Similarly if > unprepare() was called on an already-unprepared panel it was also a > no-op. Essentially it means that these functions always "forced" the > value to be whatever the caller wanted it to be. You can see that the > forcing behavior dates back at least as far as 2014 by looking at > commit 613a633e7a56 ("drm/panel: simple: Add proper definition for > prepare and unprepare"). > > Apparently the code supporting the historical behavior may not be > needed [1] and prepare() / unprepare() are supposed to be > balanced. Let's try removing it and see if anyone breaks! If they do > then we can have a debate about whether we should change that code or > revert this patch. :-) If nobody breaks then we've nicely saved a few > lines of code and some complexity. > > [1] https://lore.kernel.org/r/YHePsQgqOau1V5lD@pendragon.ideasonboard.com > Acked-by: Bjorn Andersson Regards, Bjorn > Suggested-by: Laurent Pinchart > Signed-off-by: Douglas Anderson > --- > > (no changes since v1) > > drivers/gpu/drm/panel/panel-simple.c | 14 -------------- > 1 file changed, 14 deletions(-) > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c > index 5a2953c4ca44..a2c3008af7e5 100644 > --- a/drivers/gpu/drm/panel/panel-simple.c > +++ b/drivers/gpu/drm/panel/panel-simple.c > @@ -176,8 +176,6 @@ struct panel_simple { > bool enabled; > bool no_hpd; > > - bool prepared; > - > ktime_t prepared_time; > ktime_t unprepared_time; > > @@ -355,18 +353,12 @@ static int panel_simple_suspend(struct device *dev) > > static int panel_simple_unprepare(struct drm_panel *panel) > { > - struct panel_simple *p = to_panel_simple(panel); > int ret; > > - /* Unpreparing when already unprepared is a no-op */ > - if (!p->prepared) > - return 0; > - > pm_runtime_mark_last_busy(panel->dev); > ret = pm_runtime_put_autosuspend(panel->dev); > if (ret < 0) > return ret; > - p->prepared = false; > > return 0; > } > @@ -475,18 +467,12 @@ static int panel_simple_prepare(struct drm_panel *panel) > struct panel_simple *p = to_panel_simple(panel); > int ret; > > - /* Preparing when already prepared is a no-op */ > - if (p->prepared) > - return 0; > - > ret = pm_runtime_get_sync(panel->dev); > if (ret < 0) { > pm_runtime_put_autosuspend(panel->dev); > return ret; > } > > - p->prepared = true; > - > return 0; > } > > -- > 2.31.1.368.gbe11c130af-goog > 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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 F1FE3C433ED for ; Fri, 23 Apr 2021 16:16:54 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 8C8C1611ED for ; Fri, 23 Apr 2021 16:16:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8C8C1611ED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D74416E3F7; Fri, 23 Apr 2021 16:16:53 +0000 (UTC) Received: from mail-oi1-x236.google.com (mail-oi1-x236.google.com [IPv6:2607:f8b0:4864:20::236]) by gabe.freedesktop.org (Postfix) with ESMTPS id 78CCD6E3F7 for ; Fri, 23 Apr 2021 16:16:53 +0000 (UTC) Received: by mail-oi1-x236.google.com with SMTP id i81so49669760oif.6 for ; Fri, 23 Apr 2021 09:16:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=nOQQqBqjHuvjx+mAlIOMyHNRurAecyF6kdkwHEmgzso=; b=tLZ9DmttTeYtxODA8GpoGJD3f0Haev5OEYxrAoEu5x/meFKNZ67Xrn6E7wBOaPuifI wNlvV52rK5Y2Mywj2ET9283Zs770zV7NHAs07XT9eYniS6gbUuIJBKyK+2B932VNi9sJ RcIF2vnKJocRtzBB+uIaJGPbfUfBTaB1x5X3zXN7rIb/K/+YrxSv76g7tdXH/v7NLeJF 6y4fg0IDpP2fBw3zv4WDH7ovgaWgetiGIPsn2rRTZs8FHo9D9aURjU9P8iAYP8XWlk3D AZrQ1Qqx6AtlJhlZdjsp8KQVqUuo45eacaZnE1gjIqpoB6PNVJ3i1CYRPq5KNULETOPN QidQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=nOQQqBqjHuvjx+mAlIOMyHNRurAecyF6kdkwHEmgzso=; b=Mcli/ZkQo57TiW9gFjE8Gdpf3psnVN+rZYQwWQiDbVv5DWeYoAVwvUGtMxHSKHR0Md NJoeQ7F4TSrer7rZd5PCU9VWfj7RgKZSj47KBTYRYlQH2/ZHZDlePXZC/oYDS/JcQBFE gqcYfT+z/dt5X3tRk0c0SpiluqxVi6rJgkk97k+xiIweDJ8AjPwwMPDH4KrW6qUP3kEX 0/sbh82zZjLceT0s4acE6Gb8qnuTjn8WO6YbYnf3oFpL18N/goBsEbML0Qyn0xpxFNSW uxJmExkuyRiyfjf98kV56vcof/Y+xTvWy8xP/3AAqiAckfIJBsKJlxEMD+saoPERI3E5 eHLw== X-Gm-Message-State: AOAM5302KQDoW48dhY7TCrVvvZW98JwrvrbPtXM+nxQ9khT3jf69c4AP nRiZJ2ZMi2ewR477YYYdsTkGwQ== X-Google-Smtp-Source: ABdhPJyxj8Hhn+123lQ/JT8X7RLjGQCf0dKzpHIzSwezdnqt5VNuPgWlbYaErNniQIPS+VIKQ6Nmvg== X-Received: by 2002:aca:db02:: with SMTP id s2mr4534138oig.100.1619194612825; Fri, 23 Apr 2021 09:16:52 -0700 (PDT) Received: from builder.lan (104-57-184-186.lightspeed.austtx.sbcglobal.net. [104.57.184.186]) by smtp.gmail.com with ESMTPSA id h5sm1359874oth.20.2021.04.23.09.16.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Apr 2021 09:16:52 -0700 (PDT) Date: Fri, 23 Apr 2021 11:16:50 -0500 From: Bjorn Andersson To: Douglas Anderson Subject: Re: [PATCH v4 27/27] drm/panel: panel-simple: Prepare/unprepare are refcounted, not forced Message-ID: References: <20210416223950.3586967-1-dianders@chromium.org> <20210416153909.v4.27.I502f2a92ddd36c3d28d014dd75e170c2d405a0a5@changeid> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210416153909.v4.27.I502f2a92ddd36c3d28d014dd75e170c2d405a0a5@changeid> 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: robdclark@chromium.org, Stanislav Lisovskiy , Jernej Skrabec , dri-devel@lists.freedesktop.org, Jonas Karlman , David Airlie , linux-arm-msm@vger.kernel.org, Neil Armstrong , linux-kernel@vger.kernel.org, Steev Klimaszewski , Stephen Boyd , Wolfram Sang , Andrzej Hajda , Thierry Reding , Laurent Pinchart , Sam Ravnborg Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri 16 Apr 17:39 CDT 2021, Douglas Anderson wrote: > Historically simple-panel had code to make sure that if prepare() was > called on an already-prepared panel that it was a no-op. Similarly if > unprepare() was called on an already-unprepared panel it was also a > no-op. Essentially it means that these functions always "forced" the > value to be whatever the caller wanted it to be. You can see that the > forcing behavior dates back at least as far as 2014 by looking at > commit 613a633e7a56 ("drm/panel: simple: Add proper definition for > prepare and unprepare"). > > Apparently the code supporting the historical behavior may not be > needed [1] and prepare() / unprepare() are supposed to be > balanced. Let's try removing it and see if anyone breaks! If they do > then we can have a debate about whether we should change that code or > revert this patch. :-) If nobody breaks then we've nicely saved a few > lines of code and some complexity. > > [1] https://lore.kernel.org/r/YHePsQgqOau1V5lD@pendragon.ideasonboard.com > Acked-by: Bjorn Andersson Regards, Bjorn > Suggested-by: Laurent Pinchart > Signed-off-by: Douglas Anderson > --- > > (no changes since v1) > > drivers/gpu/drm/panel/panel-simple.c | 14 -------------- > 1 file changed, 14 deletions(-) > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c > index 5a2953c4ca44..a2c3008af7e5 100644 > --- a/drivers/gpu/drm/panel/panel-simple.c > +++ b/drivers/gpu/drm/panel/panel-simple.c > @@ -176,8 +176,6 @@ struct panel_simple { > bool enabled; > bool no_hpd; > > - bool prepared; > - > ktime_t prepared_time; > ktime_t unprepared_time; > > @@ -355,18 +353,12 @@ static int panel_simple_suspend(struct device *dev) > > static int panel_simple_unprepare(struct drm_panel *panel) > { > - struct panel_simple *p = to_panel_simple(panel); > int ret; > > - /* Unpreparing when already unprepared is a no-op */ > - if (!p->prepared) > - return 0; > - > pm_runtime_mark_last_busy(panel->dev); > ret = pm_runtime_put_autosuspend(panel->dev); > if (ret < 0) > return ret; > - p->prepared = false; > > return 0; > } > @@ -475,18 +467,12 @@ static int panel_simple_prepare(struct drm_panel *panel) > struct panel_simple *p = to_panel_simple(panel); > int ret; > > - /* Preparing when already prepared is a no-op */ > - if (p->prepared) > - return 0; > - > ret = pm_runtime_get_sync(panel->dev); > if (ret < 0) { > pm_runtime_put_autosuspend(panel->dev); > return ret; > } > > - p->prepared = true; > - > return 0; > } > > -- > 2.31.1.368.gbe11c130af-goog > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel