From patchwork Sun Feb 11 09:38:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 10211237 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5CDA460236 for ; Sun, 11 Feb 2018 09:47:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4D12028EAE for ; Sun, 11 Feb 2018 09:47:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3F3C728EBB; Sun, 11 Feb 2018 09:47:23 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 051A728EAE for ; Sun, 11 Feb 2018 09:47:23 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B500B6E186; Sun, 11 Feb 2018 09:47:04 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mailout3.hostsharing.net (mailout3.hostsharing.net [176.9.242.54]) by gabe.freedesktop.org (Postfix) with ESMTPS id AD9D56E0C9; Sun, 11 Feb 2018 09:46:59 +0000 (UTC) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by mailout3.hostsharing.net (Postfix) with ESMTPS id D9D68100B08A9; Sun, 11 Feb 2018 10:39:41 +0100 (CET) Received: from localhost (6-38-90-81.adsl.cmo.de [81.90.38.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 96FB9603E052; Sun, 11 Feb 2018 10:39:30 +0100 (CET) X-Mailbox-Line: From 7831d4f21dde8cd0b1659e393854598995dfb249 Mon Sep 17 00:00:00 2001 Message-Id: <7831d4f21dde8cd0b1659e393854598995dfb249.1518338788.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Sun, 11 Feb 2018 10:38:28 +0100 Subject: [PATCH 2/5] drm: Allow determining if current task is output poll worker To: Tejun Heo , Lai Jiangshan , Alex Deucher , Dave Airlie , Ben Skeggs X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ismo Toijala , nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, Liviu Dudau , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Hans de Goede , Peter Wu MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Introduce a helper to determine if the current task is an output poll worker. This allows us to fix a long-standing deadlock in several DRM drivers wherein the ->runtime_suspend callback waits for the output poll worker to finish and the worker in turn calls a ->detect callback which waits for runtime suspend to finish. The ->detect callback is invoked from multiple call sites and waiting for runtime suspend to finish is the correct thing to do except if it's executing in the context of the worker. Cc: Dave Airlie Cc: Ben Skeggs Cc: Alex Deucher Signed-off-by: Lukas Wunner --- drivers/gpu/drm/drm_probe_helper.c | 14 ++++++++++++++ include/drm/drm_crtc_helper.h | 1 + 2 files changed, 15 insertions(+) diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 555fbe54d6e2..019881d15ce1 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -653,6 +653,20 @@ static void output_poll_execute(struct work_struct *work) schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD); } +/** + * drm_kms_helper_is_poll_worker - is %current task an output poll worker? + * + * Determine if %current task is an output poll worker. This can be used + * to select distinct code paths for output polling versus other contexts. + */ +bool drm_kms_helper_is_poll_worker(void) +{ + struct work_struct *work = current_work(); + + return work && work->func == output_poll_execute; +} +EXPORT_SYMBOL(drm_kms_helper_is_poll_worker); + /** * drm_kms_helper_poll_disable - disable output polling * @dev: drm_device diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h index 76e237bd989b..6914633037a5 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -77,5 +77,6 @@ void drm_kms_helper_hotplug_event(struct drm_device *dev); void drm_kms_helper_poll_disable(struct drm_device *dev); void drm_kms_helper_poll_enable(struct drm_device *dev); +bool drm_kms_helper_is_poll_worker(void); #endif