From nobody Thu Sep 19 23:08:11 2024 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 31DB75A110 for ; Fri, 3 May 2024 21:36:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714772204; cv=none; b=OQ61xYLbDsP/ymGkcSuEpK6uEyq9kad4+sLH/omDgspHClxgK07czdSKBAswyIVRSUazHOE5GND0DM6k74V+jsyOFebnRCtb/ZoeeKY9O57zPnMmXssXk+d8Gtf3yFOwM9FU2KaOoYk7c/z1iNPxJe9msTuijpNUULdb3Z04ipA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714772204; c=relaxed/simple; bh=nkEzB5xaPVoz6iOurmdL7HHNVRp9WgHsJcfOVLySFA8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FGZlhYiWdhtmiql6lOibM29dQfzFabhDGksTYggbpGwKobnAvnJ9BRb5TPfBywzmhX+wE1X6u4vE7c9U3WLurg5bgkGRsZ3ajHEkFp+3km9t/5moeMSpKJYWURGrowsTSCF8fNoLcdJRCOYzNDMcxYCnmLBsGG4xfSah86+3+lM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=LKU5PhFc; arc=none smtp.client-ip=209.85.214.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="LKU5PhFc" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-1e3f17c6491so780235ad.2 for ; Fri, 03 May 2024 14:36:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1714772202; x=1715377002; darn=vger.kernel.org; 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=b/gDi06ypcwTUid62LmhVpKtIZZa53PC46cbq17u59E=; b=LKU5PhFcgeyWWI9MK6J8NXiH9uW6ufi8zFcFup1fFMTibgMif+NLTnok9LuGm7OyTq ZoGDGseUNc4KksINBqRgLR+ceT+mtxIKUvcPqHB34eeWjJ8aYtwfywlI9OyM4Gyck0sl DHXwNMm8H/CajnlKwDbT+bUOAmRuk9pdJTE/g= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714772202; x=1715377002; 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=b/gDi06ypcwTUid62LmhVpKtIZZa53PC46cbq17u59E=; b=i1s44chKL0irky9+rBg3r98BU5+swaPMmO0KrzhRnz5wbi9Wxso8H/Ifwyf/MjSvpF uYgBDD2Gu+8mASS+hTQJNToSzspQFTG+YRbvPWyrrkAJWWyv48v2rqyeoNqzQ0utWvxO E2RP4OVB9P0AX2KYCgm3gls4I9fZB2aRK3yv3mbJ4OqGPkAE+mBzmvpBEyjmXTpNxWFG sIs6xpfJo8mhAXYcVq/EekiYmYtj5u6gbXC+2ThDjh3FJmMHSOHWEkx5drNiOdc5HRMs hMs2lUyClItZGNY9WPgKp3I+BD97BGCqkIuwKGrxs4vy4qEJz2b9CxVyERREjA2mBbdW iwww== X-Forwarded-Encrypted: i=1; AJvYcCWO4ASz46FlS6OCqFU3gTFusxxIFA7ZLNSm7o3An1uoWnrQokwugiiXEPhIsISLkUxhAQsv0ei9zHKUESEPvE1QmUL9NVXC85HX+UwG X-Gm-Message-State: AOJu0YzBmUARzkIj2oNRySUojrSvB2X5ko5Kl7Sz3/ysvc10s90y490i fbUjNiKjMDgLgVmcGQqd/KQYLDGPaOcjfUfv1VBDWnaTi54W+2FQMiqno0r2SA== X-Google-Smtp-Source: AGHT+IHVkT5EJTIYXQXBX5EIce/1Ex+Br0DGJO9Vob3PlE0kbtZ2ROcTXrJAG7DEeHfLLcWqrz5ILQ== X-Received: by 2002:a17:902:ce8a:b0:1e4:9ad5:a666 with SMTP id f10-20020a170902ce8a00b001e49ad5a666mr4922430plg.25.1714772202526; Fri, 03 May 2024 14:36:42 -0700 (PDT) Received: from dianders.sjc.corp.google.com ([2620:15c:9d:2:fb6a:b54b:7580:64f3]) by smtp.gmail.com with ESMTPSA id j12-20020a170903024c00b001eb51a46f5bsm3729134plh.43.2024.05.03.14.36.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 May 2024 14:36:40 -0700 (PDT) From: Douglas Anderson To: dri-devel@lists.freedesktop.org, Maxime Ripard Cc: Linus Walleij , Chris Morgan , Yuran Pereira , Neil Armstrong , Douglas Anderson , Daniel Vetter , David Airlie , Jessica Zhang , Maarten Lankhorst , Sam Ravnborg , Thomas Zimmermann , linux-kernel@vger.kernel.org Subject: [RFT PATCH v2 07/48] drm/panel: edp: Add a comment about unprepare+disable at shutdown/remove Date: Fri, 3 May 2024 14:32:48 -0700 Message-ID: <20240503143327.RFT.v2.7.Icff7f7005d997773d585e36aba9ed41a9865201f@changeid> X-Mailer: git-send-email 2.45.0.rc1.225.g2a3ae87e7f-goog In-Reply-To: <20240503213441.177109-1-dianders@chromium.org> References: <20240503213441.177109-1-dianders@chromium.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" It's the responsibility of a correctly written DRM modeset driver to call drm_atomic_helper_shutdown() at shutdown time and that should be disabling / unpreparing the panel if needed. Panel drivers shouldn't be calling these functions themselves. A recent effort was made to fix as many DRM modeset drivers as possible [1] [2] [3] and most drivers are fixed now. Unfortunately, it's very difficult to know exactly which DRM modeset drivers are using panel-edp due to the sheer number of panels it handles. For now, we'll leave the calls and just add a comment to keep people from copying this code. [1] https://lore.kernel.org/r/20230901234015.566018-1-dianders@chromium.org [2] https://lore.kernel.org/r/20230901234202.566951-1-dianders@chromium.org [3] https://lore.kernel.org/r/20230921192749.1542462-1-dianders@chromium.org Signed-off-by: Douglas Anderson --- Changes in v2: - Only handle 1 panel per patch. - Split removal of prepared/enabled from handling of remove/shutdown. - panel-edp and panel-simple just get a comment now. drivers/gpu/drm/panel/panel-edp.c | 33 +++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/pane= l-edp.c index 344f67871d41..9c4c5c0e39a3 100644 --- a/drivers/gpu/drm/panel/panel-edp.c +++ b/drivers/gpu/drm/panel/panel-edp.c @@ -944,13 +944,34 @@ static int panel_edp_probe(struct device *dev, const = struct panel_desc *desc, return err; } =20 -static void panel_edp_remove(struct device *dev) +static void panel_edp_shutdown(struct device *dev) { struct panel_edp *panel =3D dev_get_drvdata(dev); =20 - drm_panel_remove(&panel->base); + /* + * NOTE: the following two calls don't really belong here. It is the + * responsibility of a correctly written DRM modeset driver to call + * drm_atomic_helper_shutdown() at shutdown time and that should + * cause the panel to be disabled / unprepared if needed. For now, + * however, we'll keep these calls due to the sheer number of + * different DRM modeset drivers used with panel-edp. The fact that + * we're calling these and _also_ the drm_atomic_helper_shutdown() + * will try to disable/unprepare means that we can get a warning about + * trying to disable/unprepare an already disabled/unprepared panel, + * but that's something we'll have to live with until we've confirmed + * that all DRM modeset drivers are properly calling + * drm_atomic_helper_shutdown(). + */ drm_panel_disable(&panel->base); drm_panel_unprepare(&panel->base); +} + +static void panel_edp_remove(struct device *dev) +{ + struct panel_edp *panel =3D dev_get_drvdata(dev); + + drm_panel_remove(&panel->base); + panel_edp_shutdown(dev); =20 pm_runtime_dont_use_autosuspend(dev); pm_runtime_disable(dev); @@ -961,14 +982,6 @@ static void panel_edp_remove(struct device *dev) panel->drm_edid =3D NULL; } =20 -static void panel_edp_shutdown(struct device *dev) -{ - struct panel_edp *panel =3D dev_get_drvdata(dev); - - drm_panel_disable(&panel->base); - drm_panel_unprepare(&panel->base); -} - static const struct display_timing auo_b101ean01_timing =3D { .pixelclock =3D { 65300000, 72500000, 75000000 }, .hactive =3D { 1280, 1280, 1280 }, --=20 2.45.0.rc1.225.g2a3ae87e7f-goog