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 B5964C4828D for ; Tue, 6 Feb 2024 14:21:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CAA81112C39; Tue, 6 Feb 2024 14:21:15 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; secure) header.d=ffwll.ch header.i=@ffwll.ch header.b="WjKxP7BS"; dkim-atps=neutral Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8306A112C3F for ; Tue, 6 Feb 2024 14:21:14 +0000 (UTC) Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-40fc82b57f3so10065885e9.0 for ; Tue, 06 Feb 2024 06:21:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; t=1707229272; x=1707834072; darn=lists.freedesktop.org; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=7cH4cinVRUE3M6YMj8iFULuCrqzQIuc0TJaFv9jLZwc=; b=WjKxP7BSWPGsbOdpjJaYAEOwKiLAgNV2J2JijffnUCVGdfNzbN1aXZDIoE/yPYM3JW iFsOYZp1FLOGlfY7S4CFfR0HWc0Hj7q0SmNP3s8RphDTfKlt3ksa/Gh0hJv15+vYscsl mnb2/cJXfLthr07R1tBAO46/Orlbn/K01GHE8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707229272; x=1707834072; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7cH4cinVRUE3M6YMj8iFULuCrqzQIuc0TJaFv9jLZwc=; b=Fs1p3AXtVfR3pBMT5x27P4NwycNPibkk+yk6DEWdbd1YkbxfVODUqbGd2HZO89kobk EEIzMz7viVtP7pcBJVcBIOUG50da8AcOixH6/mjd3GRSBnA0BLQzubPwN8sgbVxAMTit NeuhTryafkdcvh4pGaRtTw9H0M+0HkTg8OmRx0lV8rnBx+Hkw/tMVJG7eJWd6YCBNA+0 a/H9tQ7p6BgN75UkaldbGRPjBAOAbEbefplhN3DepdY67kO1EvhVkSg3xsVDHu8du301 AW2vPTEO76CutBEwQLcTOfE4hZ7fil8UnT1W6wYNb54UEtcPS3Ft9q9q5AKL3xaLcWSC 3Tgg== X-Gm-Message-State: AOJu0YywDoLzIzct85Mjkter9m68+UhD2MpZz/tSlz9TbD+KB59PpEx6 EfMWLXPCLurQz3htINwgazkAcyknAHbzdXEKBnry1zwirtrJXWCFF46LFz2/0PI= X-Google-Smtp-Source: AGHT+IGJg0nk0Vq5ScK0sm2/0DnUB3Eu8fRzGY48sYNzv3HCToc0vt80A464uq3LIaKMXGNrCimq4A== X-Received: by 2002:a05:600c:198f:b0:40f:bda6:ccc0 with SMTP id t15-20020a05600c198f00b0040fbda6ccc0mr2335730wmq.1.1707229271976; Tue, 06 Feb 2024 06:21:11 -0800 (PST) X-Forwarded-Encrypted: i=0; AJvYcCWvfccj3dIELWNuZ5cbWBfo92YLAuBIdF79eWwOGcB5Kom+Uk02ixbChm8cD/5S6PttjMHAhAtdhWg1I0WLwY/bovMBqa01X/ydI4/Ig8k5HRGLyS+eFur1ry+MrZFzkILNN14RV5o+WbX3ny9ACTzkp6SzB/DKi0CNw9mP3CI9F5BsoGXFMAAi4nqqACvjpBEbqd0TcqZjWyPBB5BvINbp8fkWh0gHzpK5KSg90Nc2pMJqW3D6d2i8Tjih2gLR34XcCS6j2WXWqMMgskMN/iNLn+w2B8I1+eBwEzzkbBpCyL8UzYvA35lskW7YS7oE Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id u21-20020a05600c139500b0040e813f1f31sm2212377wmf.25.2024.02.06.06.21.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Feb 2024 06:21:11 -0800 (PST) Date: Tue, 6 Feb 2024 15:21:09 +0100 From: Daniel Vetter To: Daniel van Vugt Cc: Mario Limonciello , Greg Kroah-Hartman , Helge Deller , Daniel Vetter , Jani Nikula , Danilo Krummrich , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/2] fbcon: Defer console takeover for splash screens to first switch Message-ID: Mail-Followup-To: Daniel van Vugt , Mario Limonciello , Greg Kroah-Hartman , Helge Deller , Jani Nikula , Danilo Krummrich , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20240206101100.25536-1-daniel.van.vugt@canonical.com> <20240206101100.25536-2-daniel.van.vugt@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240206101100.25536-2-daniel.van.vugt@canonical.com> X-Operating-System: Linux phenom 6.6.11-amd64 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Tue, Feb 06, 2024 at 06:10:51PM +0800, Daniel van Vugt wrote: > Until now, deferred console takeover only meant defer until there is > output. But that risks stepping on the toes of userspace splash screens, > as console messages may appear before the splash screen. So check the > command line for the expectation of userspace splash and if present then > extend the deferral until after the first switch. > > V2: Added Kconfig option instead of hard coding "splash". > > Closes: https://bugs.launchpad.net/bugs/1970069 > Cc: Mario Limonciello > Signed-off-by: Daniel van Vugt > --- > drivers/video/console/Kconfig | 13 +++++++++++ > drivers/video/fbdev/core/fbcon.c | 38 ++++++++++++++++++++++++++++++-- > 2 files changed, 49 insertions(+), 2 deletions(-) > > diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig > index bc31db6ef7..a6e371bfb4 100644 > --- a/drivers/video/console/Kconfig > +++ b/drivers/video/console/Kconfig > @@ -138,6 +138,19 @@ config FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER > by the firmware in place, rather then replacing the contents with a > black screen as soon as fbcon loads. > > +config FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER_CONDITION > + string "Framebuffer Console Deferred Takeover Condition" > + depends on FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER > + default "splash" > + help > + If enabled this defers further the framebuffer console taking over > + until the first console switch has occurred. And even then only if > + text has been output, and only if the specified parameter is found > + on the command line. This ensures fbcon does not interrupt userspace > + splash screens such as Plymouth which may be yet to start rendering > + at the time of the first console output. "splash" is the simplest > + distro-agnostic condition for this that Plymouth checks for. Hm this seems a bit strange since a lot of complexity that no one needs, also my impression is that it's rather distro specific how you want this to work. So why not just a Kconfig option that lets you choose how much you want to delay fbcon setup, with the following options: - no delay at all - dely until first output from the console (which then works for distros which set a log-level to suppress unwanted stuff) - delay until first vt-switch. In that case I don't think we also need to delay for first output, since vt switch usually means you'll get first output right away (if it's a vt terminal) or you switch to a different graphical console (which will keep fbcon fully suppressed on the drm side). I think you could even reuse the existing CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER for this, and then just compile-time select which kind of notifier to register (well plus the check for "splash" on the cmdline for the vt switch one I guess). Thoughts? Cheers, Sima > + > config STI_CONSOLE > bool "STI text console" > depends on PARISC && HAS_IOMEM > diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c > index 63af6ab034..98155d2256 100644 > --- a/drivers/video/fbdev/core/fbcon.c > +++ b/drivers/video/fbdev/core/fbcon.c > @@ -76,6 +76,7 @@ > #include /* For counting font checksums */ > #include > #include > +#include > > #include "fbcon.h" > #include "fb_internal.h" > @@ -3358,6 +3359,26 @@ static int fbcon_output_notifier(struct notifier_block *nb, > > return NOTIFY_OK; > } > + > +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER_CONDITION > +static int initial_console; > +static struct notifier_block fbcon_switch_nb; > + > +static int fbcon_switch_notifier(struct notifier_block *nb, > + unsigned long action, void *data) > +{ > + struct vc_data *vc = data; > + > + WARN_CONSOLE_UNLOCKED(); > + > + if (vc->vc_num != initial_console) { > + dummycon_unregister_switch_notifier(&fbcon_switch_nb); > + dummycon_register_output_notifier(&fbcon_output_nb); > + } > + > + return NOTIFY_OK; > +} > +#endif > #endif > > static void fbcon_start(void) > @@ -3370,7 +3391,16 @@ static void fbcon_start(void) > > if (deferred_takeover) { > fbcon_output_nb.notifier_call = fbcon_output_notifier; > - dummycon_register_output_notifier(&fbcon_output_nb); > +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER_CONDITION > + if (cmdline_find_option_bool(boot_command_line, > + CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER_CONDITION)) { > + initial_console = fg_console; > + fbcon_switch_nb.notifier_call = fbcon_switch_notifier; > + dummycon_register_switch_notifier(&fbcon_switch_nb); > + } else > +#endif > + dummycon_register_output_notifier(&fbcon_output_nb); > + > return; > } > #endif > @@ -3417,8 +3447,12 @@ void __exit fb_console_exit(void) > { > #ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER > console_lock(); > - if (deferred_takeover) > + if (deferred_takeover) { > dummycon_unregister_output_notifier(&fbcon_output_nb); > +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER_CONDITION > + dummycon_unregister_switch_notifier(&fbcon_switch_nb); > +#endif > + } > console_unlock(); > > cancel_work_sync(&fbcon_deferred_takeover_work); > -- > 2.43.0 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch