Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753315AbdFOSAY (ORCPT ); Thu, 15 Jun 2017 14:00:24 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55102 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899AbdFOSAU (ORCPT ); Thu, 15 Jun 2017 14:00:20 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lyude , Hans de Goede , Kilian Singer , Lukas Wunner , David Airlie , Sasha Levin Subject: [PATCH 4.9 061/108] drm/nouveau: Handle fbcon suspend/resume in seperate worker Date: Thu, 15 Jun 2017 19:53:07 +0200 Message-Id: <20170615175340.080553689@linuxfoundation.org> X-Mailer: git-send-email 2.13.1 In-Reply-To: <20170615175337.190782107@linuxfoundation.org> References: <20170615175337.190782107@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3624 Lines: 115 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lyude Paul [ Upstream commit 15266ae38fe09dae07bd8812cb7a7717b1e1d992 ] Resuming from RPM can happen while already holding dev->mode_config.mutex. This means we can't actually handle fbcon in any RPM resume workers, since restoring fbcon requires grabbing dev->mode_config.mutex again. So move the fbcon suspend/resume code into it's own worker, and rely on that instead to avoid deadlocking. This fixes more deadlocks for runtime suspending the GPU on the ThinkPad W541. Reproduction recipe: - Get a machine with both optimus and a nvidia card with connectors attached to it - Wait for the nvidia GPU to suspend - Attempt to manually reprobe any of the connectors on the nvidia GPU using sysfs - *deadlock* [airlied: use READ_ONCE to address Hans's comment] Signed-off-by: Lyude Cc: Hans de Goede Cc: Kilian Singer Cc: Lukas Wunner Cc: David Airlie Signed-off-by: Dave Airlie Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/nouveau/nouveau_drv.h | 2 + drivers/gpu/drm/nouveau/nouveau_fbcon.c | 43 +++++++++++++++++++++++++------- 2 files changed, 36 insertions(+), 9 deletions(-) --- a/drivers/gpu/drm/nouveau/nouveau_drv.h +++ b/drivers/gpu/drm/nouveau/nouveau_drv.h @@ -164,6 +164,8 @@ struct nouveau_drm { struct nouveau_display *display; struct backlight_device *backlight; struct work_struct hpd_work; + struct work_struct fbcon_work; + int fbcon_new_state; #ifdef CONFIG_ACPI struct notifier_block acpi_nb; #endif --- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c +++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c @@ -491,19 +491,43 @@ static const struct drm_fb_helper_funcs .fb_probe = nouveau_fbcon_create, }; +static void +nouveau_fbcon_set_suspend_work(struct work_struct *work) +{ + struct nouveau_drm *drm = container_of(work, typeof(*drm), fbcon_work); + int state = READ_ONCE(drm->fbcon_new_state); + + if (state == FBINFO_STATE_RUNNING) + pm_runtime_get_sync(drm->dev->dev); + + console_lock(); + if (state == FBINFO_STATE_RUNNING) + nouveau_fbcon_accel_restore(drm->dev); + drm_fb_helper_set_suspend(&drm->fbcon->helper, state); + if (state != FBINFO_STATE_RUNNING) + nouveau_fbcon_accel_save_disable(drm->dev); + console_unlock(); + + if (state == FBINFO_STATE_RUNNING) { + pm_runtime_mark_last_busy(drm->dev->dev); + pm_runtime_put_sync(drm->dev->dev); + } +} + void nouveau_fbcon_set_suspend(struct drm_device *dev, int state) { struct nouveau_drm *drm = nouveau_drm(dev); - if (drm->fbcon) { - console_lock(); - if (state == FBINFO_STATE_RUNNING) - nouveau_fbcon_accel_restore(dev); - drm_fb_helper_set_suspend(&drm->fbcon->helper, state); - if (state != FBINFO_STATE_RUNNING) - nouveau_fbcon_accel_save_disable(dev); - console_unlock(); - } + + if (!drm->fbcon) + return; + + drm->fbcon_new_state = state; + /* Since runtime resume can happen as a result of a sysfs operation, + * it's possible we already have the console locked. So handle fbcon + * init/deinit from a seperate work thread + */ + schedule_work(&drm->fbcon_work); } int @@ -524,6 +548,7 @@ nouveau_fbcon_init(struct drm_device *de fbcon->dev = dev; drm->fbcon = fbcon; + INIT_WORK(&drm->fbcon_work, nouveau_fbcon_set_suspend_work); drm_fb_helper_prepare(dev, &fbcon->helper, &nouveau_fbcon_helper_funcs);