From patchwork Thu Aug 2 11:28:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 10553493 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C8AFB15A6 for ; Thu, 2 Aug 2018 11:28:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B53B32BCD8 for ; Thu, 2 Aug 2018 11:28:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A97BE2BCDB; Thu, 2 Aug 2018 11:28:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4D7082BCD8 for ; Thu, 2 Aug 2018 11:28:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732206AbeHBNTa (ORCPT ); Thu, 2 Aug 2018 09:19:30 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:41838 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728767AbeHBNT3 (ORCPT ); Thu, 2 Aug 2018 09:19:29 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DAB7C401DE6F; Thu, 2 Aug 2018 11:28:45 +0000 (UTC) Received: from shalem.localdomain.com (ovpn-116-163.ams2.redhat.com [10.36.116.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id 209E7215670D; Thu, 2 Aug 2018 11:28:45 +0000 (UTC) From: Hans de Goede To: Bartlomiej Zolnierkiewicz Cc: Hans de Goede , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org Subject: [PATCH fix for 4.19 2/3] fbcon: Only defer console takeover if the current console driver is the dummycon Date: Thu, 2 Aug 2018 13:28:40 +0200 Message-Id: <20180802112841.27679-3-hdegoede@redhat.com> In-Reply-To: <20180802112841.27679-1-hdegoede@redhat.com> References: <20180802112841.27679-1-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 02 Aug 2018 11:28:45 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 02 Aug 2018 11:28:45 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'hdegoede@redhat.com' RCPT:'' Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We rely on dummycon's output notifier mechanism to defer the takeover. If say vgacon is the current console driver then dummycon will never get used so its output notifier will also never get called and fbcon never takes over. This commit fixes this by only deferring the console takeover if the current console driver is the dummycon driver. This commit also moves the entirety of fbcon_start under the console_lock, since the conswitchp which fbcon_start now checks is protected by it. This commit also inlines fbcon_register_output_notifier, since we now need a #ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER in fbcon_start anyways because of the write access to the deferred_takeover variable, this has the added advantage that it puts the dummycon_register_output_notifier() call directly after the "conswitchp != &dummy_con" comparison making it clear why that check is there. Note the arch setup code will set conswitchp to either dummy_con or vga_con, in the cases where it gets set to vga_con even though their is no vga_con present we rely on vga_con_startup() to set conswitchp to dummy_con. vga_con_startup() is guaranteed to happen before fb_console_init() as it gets called as a console_initcall where as fb_console_init() gets called as a subsys_initcall. Signed-off-by: Hans de Goede --- drivers/video/fbdev/core/fbcon.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-) diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index e30d3a138c97..ef8b2d0b7071 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -3612,36 +3612,32 @@ static int fbcon_output_notifier(struct notifier_block *nb, return NOTIFY_OK; } - -static void fbcon_register_output_notifier(void) -{ - fbcon_output_nb.notifier_call = fbcon_output_notifier; - dummycon_register_output_notifier(&fbcon_output_nb); -} -#else -static inline void fbcon_register_output_notifier(void) {} #endif static void fbcon_start(void) { + WARN_CONSOLE_UNLOCKED(); + +#ifdef CONFIG_FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER + if (conswitchp != &dummy_con) + deferred_takeover = false; + if (deferred_takeover) { - fbcon_register_output_notifier(); + fbcon_output_nb.notifier_call = fbcon_output_notifier; + dummycon_register_output_notifier(&fbcon_output_nb); return; } +#endif if (num_registered_fb) { int i; - console_lock(); - for_each_registered_fb(i) { info_idx = i; break; } do_fbcon_takeover(0); - console_unlock(); - } } @@ -3724,8 +3720,8 @@ void __init fb_console_init(void) for (i = 0; i < MAX_NR_CONSOLES; i++) con2fb_map[i] = -1; - console_unlock(); fbcon_start(); + console_unlock(); } #ifdef MODULE