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: 10211235 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 0011860236 for ; Sun, 11 Feb 2018 09:47:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E3E9328EAE for ; Sun, 11 Feb 2018 09:47:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D814C28EBB; Sun, 11 Feb 2018 09:47:17 +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 7069128EAE for ; Sun, 11 Feb 2018 09:47:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 934BE6E183; Sun, 11 Feb 2018 09:47:04 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org X-Greylist: delayed 503 seconds by postgrey-1.36 at gabe; Sun, 11 Feb 2018 09:46:59 UTC Received: from mailout3.hostsharing.net (mailout3.hostsharing.net [176.9.242.54]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6C3166E066; 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 6738B101E67FB; Sun, 11 Feb 2018 10:40:26 +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 B01AE603E052; Sun, 11 Feb 2018 10:40:14 +0100 (CET) X-Mailbox-Line: From 64ea02c44f91dda19bc563902b97bbc699040392 Mon Sep 17 00:00:00 2001 Message-Id: <64ea02c44f91dda19bc563902b97bbc699040392.1518338789.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Sun, 11 Feb 2018 10:38:28 +0100 To: Tejun Heo , Lai Jiangshan , Alex Deucher , Dave Airlie , Ben Skeggs Subject: [Intel-gfx] [PATCH 4/5] drm/radeon: Fix deadlock on runtime suspend X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pierre Moreau , Archit Taneja , Ismo Toijala , nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Hans de Goede , Peter Wu MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP radeon's ->runtime_suspend hook calls drm_kms_helper_poll_disable(), which waits for the output poll worker to finish if it's running. The output poll worker meanwhile calls pm_runtime_get_sync() in radeon's ->detect hooks, which waits for the ongoing suspend to finish, causing a deadlock. Fix by not acquiring a runtime PM ref if the ->detect hooks are called in the output poll worker's context. This is safe because the poll worker is only enabled while runtime active and we know that ->runtime_suspend waits for it to finish. Stack trace for posterity: INFO: task kworker/0:3:31847 blocked for more than 120 seconds Workqueue: events output_poll_execute [drm_kms_helper] Call Trace: schedule+0x3c/0x90 rpm_resume+0x1e2/0x690 __pm_runtime_resume+0x3f/0x60 radeon_lvds_detect+0x39/0xf0 [radeon] output_poll_execute+0xda/0x1e0 [drm_kms_helper] process_one_work+0x14b/0x440 worker_thread+0x48/0x4a0 INFO: task kworker/2:0:10493 blocked for more than 120 seconds. Workqueue: pm pm_runtime_work Call Trace: schedule+0x3c/0x90 schedule_timeout+0x1b3/0x240 wait_for_common+0xc2/0x180 wait_for_completion+0x1d/0x20 flush_work+0xfc/0x1a0 __cancel_work_timer+0xa5/0x1d0 cancel_delayed_work_sync+0x13/0x20 drm_kms_helper_poll_disable+0x1f/0x30 [drm_kms_helper] radeon_pmops_runtime_suspend+0x3d/0xa0 [radeon] pci_pm_runtime_suspend+0x61/0x1a0 vga_switcheroo_runtime_suspend+0x21/0x70 __rpm_callback+0x32/0x70 rpm_callback+0x24/0x80 rpm_suspend+0x12b/0x640 pm_runtime_work+0x6f/0xb0 process_one_work+0x14b/0x440 worker_thread+0x48/0x4a0 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94147 Fixes: 10ebc0bc0934 ("drm/radeon: add runtime PM support (v2)") Cc: stable@vger.kernel.org # v3.13+: 1234567890ab: workqueue: Allow retrieval of current task's work struct Cc: stable@vger.kernel.org # v3.13+: 1234567890ab: drm: Allow determining if current task is output poll worker Cc: Ismo Toijala Cc: Alex Deucher Cc: Dave Airlie Signed-off-by: Lukas Wunner --- drivers/gpu/drm/radeon/radeon_connectors.c | 74 ++++++++++++++++++++---------- 1 file changed, 49 insertions(+), 25 deletions(-) diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c index 5012f5e47a1e..2e2ca3c6b47d 100644 --- a/drivers/gpu/drm/radeon/radeon_connectors.c +++ b/drivers/gpu/drm/radeon/radeon_connectors.c @@ -899,9 +899,11 @@ radeon_lvds_detect(struct drm_connector *connector, bool force) enum drm_connector_status ret = connector_status_disconnected; int r; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } if (encoder) { struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder); @@ -924,8 +926,12 @@ radeon_lvds_detect(struct drm_connector *connector, bool force) /* check acpi lid status ??? */ radeon_connector_update_scratch_regs(connector, ret); - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } + return ret; } @@ -1039,9 +1045,11 @@ radeon_vga_detect(struct drm_connector *connector, bool force) enum drm_connector_status ret = connector_status_disconnected; int r; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } encoder = radeon_best_single_encoder(connector); if (!encoder) @@ -1108,8 +1116,10 @@ radeon_vga_detect(struct drm_connector *connector, bool force) radeon_connector_update_scratch_regs(connector, ret); out: - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } return ret; } @@ -1173,9 +1183,11 @@ radeon_tv_detect(struct drm_connector *connector, bool force) if (!radeon_connector->dac_load_detect) return ret; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } encoder = radeon_best_single_encoder(connector); if (!encoder) @@ -1187,8 +1199,12 @@ radeon_tv_detect(struct drm_connector *connector, bool force) if (ret == connector_status_connected) ret = radeon_connector_analog_encoder_conflict_solve(connector, encoder, ret, false); radeon_connector_update_scratch_regs(connector, ret); - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } + return ret; } @@ -1251,9 +1267,11 @@ radeon_dvi_detect(struct drm_connector *connector, bool force) enum drm_connector_status ret = connector_status_disconnected; bool dret = false, broken_edid = false; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } if (radeon_connector->detected_hpd_without_ddc) { force = true; @@ -1436,8 +1454,10 @@ radeon_dvi_detect(struct drm_connector *connector, bool force) } exit: - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } return ret; } @@ -1688,9 +1708,11 @@ radeon_dp_detect(struct drm_connector *connector, bool force) if (radeon_dig_connector->is_mst) return connector_status_disconnected; - r = pm_runtime_get_sync(connector->dev->dev); - if (r < 0) - return connector_status_disconnected; + if (!drm_kms_helper_is_poll_worker()) { + r = pm_runtime_get_sync(connector->dev->dev); + if (r < 0) + return connector_status_disconnected; + } if (!force && radeon_check_hpd_status_unchanged(connector)) { ret = connector->status; @@ -1777,8 +1799,10 @@ radeon_dp_detect(struct drm_connector *connector, bool force) } out: - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); + if (!drm_kms_helper_is_poll_worker()) { + pm_runtime_mark_last_busy(connector->dev->dev); + pm_runtime_put_autosuspend(connector->dev->dev); + } return ret; }