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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDB6DFA3740 for ; Thu, 27 Oct 2022 16:55:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235132AbiJ0Qzs (ORCPT ); Thu, 27 Oct 2022 12:55:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234730AbiJ0Qzr (ORCPT ); Thu, 27 Oct 2022 12:55:47 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2FB4DD259D; Thu, 27 Oct 2022 09:55:46 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D6D39B82708; Thu, 27 Oct 2022 16:55:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13398C433D6; Thu, 27 Oct 2022 16:55:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666889743; bh=+NQUXBWxMDcjKd1qUF+jvvhREtcMHvY+4DvsYClRT6U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qfK3QytRTz9gi6rbnb9CHEVnWlw1M+Jv3rZ69K57vHapAajNj9PfKFi5MT4NbLTok FW9dGhlP5DQR/im7tnt/sj8hlG7ltxzLggfo/ISEgskJ9jrlinIAZfAoDd5HGgArs/ tF3x2ZQZLdT09hTzY/hmDaSPHZ2OC+Z9jD14RzlM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Andreas Thalhammer , Thorsten Leemhuis , Thomas Zimmermann , Javier Martinez Canillas , Zack Rusin , Daniel Vetter , Daniel Vetter , Sam Ravnborg , Helge Deller , Alex Deucher , Zhen Lei , Changcheng Deng , Maarten Lankhorst , Maxime Ripard , dri-devel@lists.freedesktop.org, Sasha Levin , linux-fbdev@vger.kernel.org Subject: [PATCH 6.0 01/94] [PATCH v2] video/aperture: Call sysfb_disable() before removing PCI devices Date: Thu, 27 Oct 2022 18:54:03 +0200 Message-Id: <20221027165057.255751031@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221027165057.208202132@linuxfoundation.org> References: <20221027165057.208202132@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org From: Thomas Zimmermann Call sysfb_disable() from aperture_remove_conflicting_pci_devices() before removing PCI devices. Without, simpledrm can still bind to simple-framebuffer devices after the hardware driver has taken over the hardware. Both drivers interfere with each other and results are undefined. Reported modesetting errors [1] are shown below. ---- snap ---- rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 13-.... } 7 jiffies s: 165 root: 0x2000/. rcu: blocking rcu_node structures (internal RCU debug): Task dump for CPU 13: task:X state:R running task stack: 0 pid: 4242 ppid: 4228 flags:0x00000008 Call Trace: ? commit_tail+0xd7/0x130 ? drm_atomic_helper_commit+0x126/0x150 ? drm_atomic_commit+0xa4/0xe0 ? drm_plane_get_damage_clips.cold+0x1c/0x1c ? drm_atomic_helper_dirtyfb+0x19e/0x280 ? drm_mode_dirtyfb_ioctl+0x10f/0x1e0 ? drm_mode_getfb2_ioctl+0x2d0/0x2d0 ? drm_ioctl_kernel+0xc4/0x150 ? drm_ioctl+0x246/0x3f0 ? drm_mode_getfb2_ioctl+0x2d0/0x2d0 ? __x64_sys_ioctl+0x91/0xd0 ? do_syscall_64+0x60/0xd0 ? entry_SYSCALL_64_after_hwframe+0x4b/0xb5 ... rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 13-.... } 30 jiffies s: 169 root: 0x2000/. rcu: blocking rcu_node structures (internal RCU debug): Task dump for CPU 13: task:X state:R running task stack: 0 pid: 4242 ppid: 4228 flags:0x0000400e Call Trace: ? memcpy_toio+0x76/0xc0 ? memcpy_toio+0x1b/0xc0 ? drm_fb_memcpy_toio+0x76/0xb0 ? drm_fb_blit_toio+0x75/0x2b0 ? simpledrm_simple_display_pipe_update+0x132/0x150 ? drm_atomic_helper_commit_planes+0xb6/0x230 ? drm_atomic_helper_commit_tail+0x44/0x80 ? commit_tail+0xd7/0x130 ? drm_atomic_helper_commit+0x126/0x150 ? drm_atomic_commit+0xa4/0xe0 ? drm_plane_get_damage_clips.cold+0x1c/0x1c ? drm_atomic_helper_dirtyfb+0x19e/0x280 ? drm_mode_dirtyfb_ioctl+0x10f/0x1e0 ? drm_mode_getfb2_ioctl+0x2d0/0x2d0 ? drm_ioctl_kernel+0xc4/0x150 ? drm_ioctl+0x246/0x3f0 ? drm_mode_getfb2_ioctl+0x2d0/0x2d0 ? __x64_sys_ioctl+0x91/0xd0 ? do_syscall_64+0x60/0xd0 ? entry_SYSCALL_64_after_hwframe+0x4b/0xb5 The problem was added by commit 5e0137612430 ("video/aperture: Disable and unregister sysfb devices via aperture helpers") to v6.0.3 and does not exist in the mainline branch. The mainline commit 5e0137612430 ("video/aperture: Disable and unregister sysfb devices via aperture helpers") has been backported from v6.0-rc1 to stable v6.0.3 from a larger patch series [2] that reworks fbdev framebuffer ownership. The backport misses a change to aperture_remove_conflicting_pci_devices(). Mainline itself is fine, because the function does not exist there as a result of the patch series. Instead of backporting the whole series, fix the additional function. Reported-by: Andreas Thalhammer Reported-by: Thorsten Leemhuis Signed-off-by: Thomas Zimmermann Tested-by: Andreas Thalhammer Fixes: cfecfc98a78d ("video/aperture: Disable and unregister sysfb devices via aperture helpers") Cc: Thomas Zimmermann Cc: Javier Martinez Canillas Cc: Zack Rusin Cc: Daniel Vetter Cc: Daniel Vetter Cc: Sam Ravnborg Cc: Helge Deller Cc: Alex Deucher Cc: Zhen Lei Cc: Changcheng Deng Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: dri-devel@lists.freedesktop.org Cc: Sasha Levin Cc: linux-fbdev@vger.kernel.org Cc: # v6.0.3+ Link: https://lore.kernel.org/dri-devel/d6afe54b-f8d7-beb2-3609-186e566cbfac@gmx.net/T/#t # [1] Link: https://patchwork.freedesktop.org/series/106040/ # [2] Signed-off-by: Greg Kroah-Hartman --- drivers/video/aperture.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/video/aperture.c +++ b/drivers/video/aperture.c @@ -358,6 +358,17 @@ int aperture_remove_conflicting_pci_devi return ret; /* + * 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(); + + /* * WARNING: Apparently we must kick fbdev drivers before vgacon, * otherwise the vga fbdev driver falls over. */