From patchwork Tue Jul 25 20:34:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 13326992 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 B6990C00528 for ; Tue, 25 Jul 2023 20:37:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231211AbjGYUhK (ORCPT ); Tue, 25 Jul 2023 16:37:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231209AbjGYUhG (ORCPT ); Tue, 25 Jul 2023 16:37:06 -0400 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 271601BF6 for ; Tue, 25 Jul 2023 13:37:00 -0700 (PDT) Received: by mail-pf1-x432.google.com with SMTP id d2e1a72fcca58-686be3cbea0so156741b3a.0 for ; Tue, 25 Jul 2023 13:37:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1690317419; x=1690922219; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=iP077J8EmgyqkeILX2Yz7pVClwWU9gA5lNNcugVIOYM=; b=GZtIAhgpfRM6/PPCpYhDawEQ6STVkqSIEtcARCGIslDV0E2Oz5EubU2sXZt7Y5WysZ nKHRRDgxz+IHkbiAD+r0tr3hYj9QMJNtPXWKWcYKUibKzK1RlYALHKuldQpyQ+rjq2tC vqm+0xJeEEXyQUwsjDBcku/nb5WAuu2nfu6Mw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690317419; x=1690922219; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iP077J8EmgyqkeILX2Yz7pVClwWU9gA5lNNcugVIOYM=; b=Ji7E5tPN0HDFGeih3UBaEKrIaJERGEvO/pDg37glZ/iMIilj/CrTgCgKwBQvtirMhA 8z5qjf4KhWKvBojIt9YMw9UzrwHGvuZO4cJI2j9Gk+MAwdeuJifQtzIS6qkgIV5Mqb0E jnHOymzx2ZEOhHJosXb21kVBOSmNbykveONwP7WsEkrCoh6ERRjkOa/hKZQezaG4W4UL PQ6eyUlvKFCYWTSq0x/OHPHRr7SAvnTXRU+MystQW55guZ0mHcNF5nJZLY5icgXd5Oje mHt2kB73is3bn7nW0G96kEs/mgQac1I4TGZy6FnQP/hpOnBoATPF1LgybzbwrnpWLsUt r8xA== X-Gm-Message-State: ABy/qLaz58PWDfdNpK9ElR+sTC7np4zAVlOAa2jQvp6wsHNq9mr8W9fa aDNlqOY4PmXj9HoVZFW9yd1+Vg== X-Google-Smtp-Source: APBJJlGIYTwndwxiNhy3tq6Tp8y0sx+SY03ysIcCBnr6qkE2JXCztECD/+Fst0vDsbRKfMcVyfODkg== X-Received: by 2002:a17:90a:4a8e:b0:268:e3d:1251 with SMTP id f14-20020a17090a4a8e00b002680e3d1251mr269480pjh.20.1690317419541; Tue, 25 Jul 2023 13:36:59 -0700 (PDT) Received: from tictac2.mtv.corp.google.com ([2620:15c:9d:2:c363:4681:f5b8:301]) by smtp.gmail.com with ESMTPSA id bg1-20020a17090b0d8100b002676e961261sm1396951pjb.1.2023.07.25.13.36.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Jul 2023 13:36:58 -0700 (PDT) From: Douglas Anderson To: Jiri Kosina , Benjamin Tissoires , Bjorn Andersson , Konrad Dybcio , Rob Herring , Frank Rowand , Krzysztof Kozlowski , Conor Dooley , Neil Armstrong , Sam Ravnborg , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann Cc: cros-qcom-dts-watchers@chromium.org, Chris Morgan , linux-input@vger.kernel.org, hsinyi@google.com, linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Dmitry Torokhov , devicetree@vger.kernel.org, Daniel Vetter , yangcong5@huaqin.corp-partner.google.com, Douglas Anderson Subject: [PATCH v3 02/10] drm/panel: Check for already prepared/enabled in drm_panel Date: Tue, 25 Jul 2023 13:34:37 -0700 Message-ID: <20230725133443.v3.2.I59b417d4c29151cc2eff053369ec4822b606f375@changeid> X-Mailer: git-send-email 2.41.0.487.g6d72f3e995-goog In-Reply-To: <20230725203545.2260506-1-dianders@chromium.org> References: <20230725203545.2260506-1-dianders@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org In a whole pile of panel drivers, we have code to make the prepare/unprepare/enable/disable callbacks behave as no-ops if they've already been called. It's silly to have this code duplicated everywhere. Add it to the core instead so that we can eventually delete it from all the drivers. Note: to get some idea of the duplicated code, try: git grep 'if.*>prepared' -- drivers/gpu/drm/panel git grep 'if.*>enabled' -- drivers/gpu/drm/panel NOTE: arguably, the right thing to do here is actually to skip this patch and simply remove all the extra checks from the individual drivers. Perhaps the checks were needed at some point in time in the past but maybe they no longer are? Certainly as we continue transitioning over to "panel_bridge" then we expect there to be much less variety in how these calls are made. When we're called as part of the bridge chain, things should be pretty simple. In fact, there was some discussion in the past about these checks [1], including a discussion about whether the checks were needed and whether the calls ought to be refcounted. At the time, I decided not to mess with it because it felt too risky. Looking closer at it now, I'm fairly certain that nothing in the existing codebase is expecting these calls to be refcounted. The only real question is whether someone is already doing something to ensure prepare()/unprepare() match and enabled()/disable() match. I would say that, even if there is something else ensuring that things match, there's enough complexity that adding an extra bool and an extra double-check here is a good idea. Let's add a drm_warn() to let people know that it's considered a minor error to take advantage of drm_panel's double-checking but we'll still make things work fine. [1] https://lore.kernel.org/r/20210416153909.v4.27.I502f2a92ddd36c3d28d014dd75e170c2d405a0a5@changeid Acked-by: Neil Armstrong Signed-off-by: Douglas Anderson --- This has Neil's Ack and I could commit it to drm-misc-next, but for now I'm holding off to see where this series ends up. If the series ends up looking good we'll have to coordinate landing the various bits between the drm and the hid trees and the second drm patch in my series depends on this one. If my series implodes I'll land this one on its own. In any case, once this lands somewhere I'll take an AI to cleanup the panels. (no changes since v1) drivers/gpu/drm/drm_panel.c | 49 ++++++++++++++++++++++++++++++++----- include/drm/drm_panel.h | 14 +++++++++++ 2 files changed, 57 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index f634371c717a..4e1c4e42575b 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -105,11 +105,22 @@ EXPORT_SYMBOL(drm_panel_remove); */ int drm_panel_prepare(struct drm_panel *panel) { + int ret; + if (!panel) return -EINVAL; - if (panel->funcs && panel->funcs->prepare) - return panel->funcs->prepare(panel); + if (panel->prepared) { + dev_warn(panel->dev, "Skipping prepare of already prepared panel\n"); + return 0; + } + + if (panel->funcs && panel->funcs->prepare) { + ret = panel->funcs->prepare(panel); + if (ret < 0) + return ret; + } + panel->prepared = true; return 0; } @@ -128,11 +139,22 @@ EXPORT_SYMBOL(drm_panel_prepare); */ int drm_panel_unprepare(struct drm_panel *panel) { + int ret; + if (!panel) return -EINVAL; - if (panel->funcs && panel->funcs->unprepare) - return panel->funcs->unprepare(panel); + if (!panel->prepared) { + dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n"); + return 0; + } + + if (panel->funcs && panel->funcs->unprepare) { + ret = panel->funcs->unprepare(panel); + if (ret < 0) + return ret; + } + panel->prepared = false; return 0; } @@ -155,11 +177,17 @@ int drm_panel_enable(struct drm_panel *panel) if (!panel) return -EINVAL; + if (panel->enabled) { + dev_warn(panel->dev, "Skipping enable of already enabled panel\n"); + return 0; + } + if (panel->funcs && panel->funcs->enable) { ret = panel->funcs->enable(panel); if (ret < 0) return ret; } + panel->enabled = true; ret = backlight_enable(panel->backlight); if (ret < 0) @@ -187,13 +215,22 @@ int drm_panel_disable(struct drm_panel *panel) if (!panel) return -EINVAL; + if (!panel->enabled) { + dev_warn(panel->dev, "Skipping disable of already disabled panel\n"); + return 0; + } + ret = backlight_disable(panel->backlight); if (ret < 0) DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n", ret); - if (panel->funcs && panel->funcs->disable) - return panel->funcs->disable(panel); + if (panel->funcs && panel->funcs->disable) { + ret = panel->funcs->disable(panel); + if (ret < 0) + return ret; + } + panel->enabled = false; return 0; } diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 432fab2347eb..c6cf75909389 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -198,6 +198,20 @@ struct drm_panel { * the panel is powered up. */ bool prepare_prev_first; + + /** + * @prepared: + * + * If true then the panel has been prepared. + */ + bool prepared; + + /** + * @enabled: + * + * If true then the panel has been enabled. + */ + bool enabled; }; void drm_panel_init(struct drm_panel *panel, struct device *dev,