From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELsMFN/VirQsOrDohUtUj/ltRWm37tsmeQvIh4MCBrl1CR4VkJYjTg+eQxbieVLVSRvz1pFs ARC-Seal: i=1; a=rsa-sha256; t=1520955496; cv=none; d=google.com; s=arc-20160816; b=H90OS7vdUUnIUr5WgoH/AW/tOkmfLnnLFGOc49GIBoT9K/cPcDSqaC9gOC0fzs1e1r 4DCK8zj4HtG+snkb53tlIXDZyago8YllijRCzC9BwD7b0SDh6ILWTTN4JF6PzF09Ixms S8YxXYdCzcLhmqsXSLs89ceibjp3tgKNk6BFHiY4cVHSLpBFRq3gAM/K1bM4FATuhiMM 5p3CVPMc7sjpteIc/rmkmRW7U6oFM9i7D3mLmEYxE7F6Oz1p7TU5HwK34sE04YICpm2c bXWmKSpEPlup6N8brUcqmtQCXTWeKaZUXLzpMXxl7brUOIh/+gjVG+TcXzyCEHYuyr5N Qm4g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=R92wJAlrnbZAzKTRbYNjfKuMlEEC5kibjPNLPpCos5c=; b=tBVSs7mYLgFEnUMQ2mEDm4q6gW/kEL1BaT3safOnoxHRgNKMbCxEhpOQlt19a015dn jCRAmDG+eA6XzHN5hg9zNM6F8mFoC1qgkQEHBZwLoZG6Tt4rN5rROjYYfu0C8ew9XhXw 0dfRjoL+ckbenn+SttJ88zoNoVpSlLwegThz4TEidLgSZviavzmUWyUODAup2sKeNfjX uBbNNmjPj6ILmbiu2gGPn+zGUo6Qs4ADCjHT93uPx8SbMaglRlQQROsEhE1IJ2XHp+2o lE/j6+1ftYA0ztzQkGeB9npxhAtjntYfhn9yARK3CyC0ktCLb2yLt5/ACPaAbwlzSmx2 nOig== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ismo Toijala , Alex Deucher , Dave Airlie , Lyude Paul , Lukas Wunner Subject: [PATCH 4.14 064/140] drm/radeon: Fix deadlock on runtime suspend Date: Tue, 13 Mar 2018 16:24:27 +0100 Message-Id: <20180313152502.512398916@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180313152458.201155692@linuxfoundation.org> References: <20180313152458.201155692@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1594836810214398214?= X-GMAIL-MSGID: =?utf-8?q?1594837430197562929?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lukas Wunner commit 15734feff2bdac24aa3266c437cffa42851990e3 upstream. 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+: 27d4ee03078a: workqueue: Allow retrieval of current task's work struct Cc: stable@vger.kernel.org # v3.13+: 25c058ccaf2e: drm: Allow determining if current task is output poll worker Cc: Ismo Toijala Cc: Alex Deucher Cc: Dave Airlie Reviewed-by: Lyude Paul Signed-off-by: Lukas Wunner Link: https://patchwork.freedesktop.org/patch/msgid/64ea02c44f91dda19bc563902b97bbc699040392.1518338789.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/radeon/radeon_connectors.c | 74 +++++++++++++++++++---------- 1 file changed, 49 insertions(+), 25 deletions(-) --- a/drivers/gpu/drm/radeon/radeon_connectors.c +++ b/drivers/gpu/drm/radeon/radeon_connectors.c @@ -900,9 +900,11 @@ radeon_lvds_detect(struct drm_connector 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); @@ -925,8 +927,12 @@ radeon_lvds_detect(struct drm_connector /* 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; } @@ -1040,9 +1046,11 @@ radeon_vga_detect(struct drm_connector * 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) @@ -1109,8 +1117,10 @@ radeon_vga_detect(struct drm_connector * 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; } @@ -1174,9 +1184,11 @@ radeon_tv_detect(struct drm_connector *c 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) @@ -1188,8 +1200,12 @@ radeon_tv_detect(struct drm_connector *c 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; } @@ -1252,9 +1268,11 @@ radeon_dvi_detect(struct drm_connector * 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; @@ -1437,8 +1455,10 @@ out: } 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; } @@ -1689,9 +1709,11 @@ radeon_dp_detect(struct drm_connector *c 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; @@ -1778,8 +1800,10 @@ radeon_dp_detect(struct drm_connector *c } 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; }