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[92.176.231.205]) by smtp.gmail.com with ESMTPSA id m8-20020a05600c4f4800b003942a244f51sm28267502wmq.42.2022.06.07.11.23.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jun 2022 11:23:48 -0700 (PDT) From: Javier Martinez Canillas To: linux-kernel@vger.kernel.org Cc: dri-devel@lists.freedesktop.org, Thomas Zimmermann , Laszlo Ersek , Alex Williamson , Gerd Hoffmann , kvm@vger.kernel.org, Greg Kroah-Hartman , Daniel Vetter , Javier Martinez Canillas , Daniel Vetter , Helge Deller , linux-fbdev@vger.kernel.org Subject: [PATCH v6 3/5] fbdev: Disable sysfb device registration when removing conflicting FBs Date: Tue, 7 Jun 2022 20:23:36 +0200 Message-Id: <20220607182338.344270-4-javierm@redhat.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607182338.344270-1-javierm@redhat.com> References: <20220607182338.344270-1-javierm@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org The platform devices registered by sysfb match with firmware-based DRM or fbdev drivers, that are used to have early graphics using a framebuffer provided by the system firmware. DRM or fbdev drivers later are probed and remove all conflicting framebuffers, leading to these platform devices for generic drivers to be unregistered. But the current solution has a race, since the sysfb_init() function could be called after a DRM or fbdev driver is probed and request to unregister the devices for drivers with conflicting framebuffes. To prevent this, disable any future sysfb platform device registration by calling sysfb_disable(), if a driver requests to remove the conflicting framebuffers. Suggested-by: Daniel Vetter Signed-off-by: Javier Martinez Canillas Reviewed-by: Daniel Vetter --- Changes in v6: - Move the sysfb_disable() before the remove conflicting framebuffers loop (Daniel Vetter). Changes in v5: - Move the sysfb_disable() call at conflicting framebuffers again to avoid the need of a DRIVER_FIRMWARE capability flag. - Add Daniel Vetter's Reviewed-by tag again since reverted to the old patch that he already reviewed in v2. Changes in v3: - Call sysfb_disable() when a DRM dev and a fbdev are registered rather than when conflicting framebuffers are removed (Thomas Zimmermann). - Call sysfb_disable() when a fbdev framebuffer is registered rather than when conflicting framebuffers are removed (Thomas Zimmermann). - Drop Daniel Vetter's Reviewed-by tag since patch changed a lot. Changes in v2: - Explain in the commit message that fbmem has to unregister the device as fallback if a driver registered the device itself (Daniel Vetter). - Also explain that fallback in a comment in the code (Daniel Vetter). - Don't encode in fbmem the assumption that sysfb will always register platform devices (Daniel Vetter). - Add a FIXME comment about drivers registering devices (Daniel Vetter). drivers/video/fbdev/core/fbmem.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 2fda5917c212..e0720fef0ee6 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -1764,6 +1765,17 @@ int remove_conflicting_framebuffers(struct apertures_struct *a, do_free = true; } + /* + * If a driver asked to unregister a platform device registered by + * sysfb, then can be assumed that this is a driver for a display + * that is set up by the system firmware and has a generic driver. + * + * Drivers for devices that don't have a generic driver will never + * ask for this, so let's assume that a real driver for the display + * was already probed and prevent sysfb to register devices later. + */ + sysfb_disable(); + mutex_lock(®istration_lock); do_remove_conflicting_framebuffers(a, name, primary); mutex_unlock(®istration_lock); From patchwork Tue Jun 7 18:23:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Javier Martinez Canillas X-Patchwork-Id: 579636 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 7D6B1C433EF for ; Tue, 7 Jun 2022 19:59:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357796AbiFGT7r (ORCPT ); Tue, 7 Jun 2022 15:59:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357935AbiFGT7C (ORCPT ); Tue, 7 Jun 2022 15:59:02 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 407E01BBADA for ; Tue, 7 Jun 2022 11:24:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1654626234; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=P4f3wHn7jIrIURtw341a5ADfTmzk5i8t59cyMFQz5Qc=; b=Xw4HHWK9BFohqfbyqXsndyNgX19ayI7Gri9nvVyAhnDSAS69b3VGCx5V+2JkJo2Pm6n78f eOdI75AOMO6uAafiZiDTCndifelG6JaNCAf8WoiJt5UZ9yJRsS5kMvG62DbTJNUVKqbBy3 1S7frUjuyDro36D10+XguV9r3j4lLVc= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-351-Vv_cJYZSPYqWgVCPWUplhw-1; Tue, 07 Jun 2022 14:23:53 -0400 X-MC-Unique: Vv_cJYZSPYqWgVCPWUplhw-1 Received: by mail-wr1-f70.google.com with SMTP id c11-20020adffb4b000000b0020ff998391dso4179894wrs.8 for ; Tue, 07 Jun 2022 11:23:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=P4f3wHn7jIrIURtw341a5ADfTmzk5i8t59cyMFQz5Qc=; b=xr1bZAq7L5+pVxgOGL7VRdz5o5WywmFHi1wf2kE9SKjncJSCGqeGvpYnn9Z9uEam+D 315XGPnLFx/HkmRIolSsuF2lr34kdCGzqIKWN8Oyvwd5euZN+19Uw+GqCIotKXdaA2O8 k7WPuyC2+UNqu7kplUp1VbfrbhvcbQcTDZoTfjh9ghzHTA2HJp+9lf+6O4MghXbl6KUZ FUqNDeIIVuxfke8rh3+huK6z//s94P55xUEGWzqnW5qP3E+PGti/W0ivPsJXddvmCncC M8KxIP65769flv9/roasZ7tfaMbfvciY+aicdWqgBcTqsLwfS8JozvIg23EYxdj7Hbuk WhCw== X-Gm-Message-State: AOAM530xKs8xdwNCZeCow7jg2esGSDjlW65vQrPZ7fxaZH+KJJkxSAZy oyW4h65rA1hA5CcArSAfrI+zz/+H+Y4EhrC3fRc8jrUOSvZxedibPWgrRUKfbxgqhIBlf+c/vyH FevOmQHmzFaooeGWP3YcGEac= X-Received: by 2002:a05:6000:711:b0:217:371e:b7ff with SMTP id bs17-20020a056000071100b00217371eb7ffmr16261823wrb.127.1654626232063; Tue, 07 Jun 2022 11:23:52 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx/N4WjMmddIXMJgSScZ/qUGCGSnIp6UQDq474dS3NmqfffRft8Ws4ePchj9FzlpDpPJ0DOSA== X-Received: by 2002:a05:6000:711:b0:217:371e:b7ff with SMTP id bs17-20020a056000071100b00217371eb7ffmr16261787wrb.127.1654626231742; Tue, 07 Jun 2022 11:23:51 -0700 (PDT) Received: from minerva.home (205.pool92-176-231.dynamic.orange.es. [92.176.231.205]) by smtp.gmail.com with ESMTPSA id m8-20020a05600c4f4800b003942a244f51sm28267502wmq.42.2022.06.07.11.23.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jun 2022 11:23:51 -0700 (PDT) From: Javier Martinez Canillas To: linux-kernel@vger.kernel.org Cc: dri-devel@lists.freedesktop.org, Thomas Zimmermann , Laszlo Ersek , Alex Williamson , Gerd Hoffmann , kvm@vger.kernel.org, Greg Kroah-Hartman , Daniel Vetter , kernel test robot , Jens Frederich , Jon Nettleton , linux-staging@lists.linux.dev, Daniel Vetter , Javier Martinez Canillas , Daniel Vetter , Helge Deller , Matthew Wilcox , Sam Ravnborg , Tetsuo Handa , Zhen Lei , Alex Deucher , Xiyu Yang , linux-fbdev@vger.kernel.org, Zheyu Ma , Guenter Roeck Subject: [PATCH v6 5/5] fbdev: Make registered_fb[] private to fbmem.c Date: Tue, 7 Jun 2022 20:23:38 +0200 Message-Id: <20220607182338.344270-6-javierm@redhat.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607182338.344270-1-javierm@redhat.com> References: <20220607182338.344270-1-javierm@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org From: Daniel Vetter Well except when the olpc dcon fbdev driver is enabled, that thing digs around in there in rather unfixable ways. Cc oldc_dcon maintainers as fyi. v2: I typoed the config name (0day) Cc: kernel test robot Cc: Jens Frederich Cc: Jon Nettleton Cc: Greg Kroah-Hartman Cc: linux-staging@lists.linux.dev Signed-off-by: Daniel Vetter Signed-off-by: Daniel Vetter Reviewed-by: Javier Martinez Canillas Cc: Daniel Vetter Cc: Helge Deller Cc: Matthew Wilcox Cc: Sam Ravnborg Cc: Tetsuo Handa Cc: Zhen Lei Cc: Alex Deucher Cc: Xiyu Yang Cc: linux-fbdev@vger.kernel.org Cc: Zheyu Ma Cc: Guenter Roeck Signed-off-by: Javier Martinez Canillas --- (no changes since v1) drivers/video/fbdev/core/fbmem.c | 8 ++++++-- include/linux/fb.h | 7 +++---- 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index e0720fef0ee6..bdb08b665b43 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -50,10 +50,14 @@ static DEFINE_MUTEX(registration_lock); struct fb_info *registered_fb[FB_MAX] __read_mostly; -EXPORT_SYMBOL(registered_fb); - int num_registered_fb __read_mostly; +#if IS_ENABLED(CONFIG_FB_OLPC_DCON) +EXPORT_SYMBOL(registered_fb); EXPORT_SYMBOL(num_registered_fb); +#endif +#define for_each_registered_fb(i) \ + for (i = 0; i < FB_MAX; i++) \ + if (!registered_fb[i]) {} else bool fb_center_logo __read_mostly; diff --git a/include/linux/fb.h b/include/linux/fb.h index bbe1e4571899..c563e24b6293 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -632,16 +632,15 @@ extern int fb_get_color_depth(struct fb_var_screeninfo *var, extern int fb_get_options(const char *name, char **option); extern int fb_new_modelist(struct fb_info *info); +#if IS_ENABLED(CONFIG_FB_OLPC_DCON) extern struct fb_info *registered_fb[FB_MAX]; + extern int num_registered_fb; +#endif extern bool fb_center_logo; extern int fb_logo_count; extern struct class *fb_class; -#define for_each_registered_fb(i) \ - for (i = 0; i < FB_MAX; i++) \ - if (!registered_fb[i]) {} else - static inline void lock_fb_info(struct fb_info *info) { mutex_lock(&info->lock);