Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753493AbdDKU6T (ORCPT ); Tue, 11 Apr 2017 16:58:19 -0400 Received: from regular1.263xmail.com ([211.150.99.137]:38506 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752246AbdDKU6Q (ORCPT ); Tue, 11 Apr 2017 16:58:16 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: jeffy.chen@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: jeffy.chen@rock-chips.com X-UNIQUE-TAG: <762b1d35d51557607d97df69a6e6e8d0> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: Jeffy Chen To: linux-kernel@vger.kernel.org Cc: briannorris@chromium.org, dianders@chromium.org, tfiga@chromium.org, seanpaul@chromium.org, zyw@rock-chips.com, marcheu@chromium.org, mark.yao@rock-chips.com, hshi@chromium.org, Jeffy Chen , Daniel Vetter , Jani Nikula , dri-devel@lists.freedesktop.org, David Airlie Subject: [PATCH] drm: Fixup hang when unregistering drm dev with open_count 0 Date: Wed, 12 Apr 2017 04:57:54 +0800 Message-Id: <1491944274-29007-1-git-send-email-jeffy.chen@rock-chips.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1854 Lines: 64 My previous patch (c5d8fac2bf drm: Unplug drm device when unregistering it) calls drm_unplug_dev when unregistering drm dev. But if open_count is 0, the unplug will try to unregister the drm dev again and cause deadlock. Fix it by dropping drm_unplug_dev and use drm_device_set_plug_state directly. Signed-off-by: Jeffy Chen --- drivers/gpu/drm/drm_drv.c | 15 +-------------- include/drm/drm_drv.h | 1 - 2 files changed, 1 insertion(+), 15 deletions(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index ad13e20..cc2d018 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -355,19 +355,6 @@ void drm_put_dev(struct drm_device *dev) } EXPORT_SYMBOL(drm_put_dev); -void drm_unplug_dev(struct drm_device *dev) -{ - mutex_lock(&drm_global_mutex); - - drm_device_set_plug_state(dev, false); - - if (dev->open_count == 0) { - drm_put_dev(dev); - } - mutex_unlock(&drm_global_mutex); -} -EXPORT_SYMBOL(drm_unplug_dev); - /* * DRM internal mount * We want to be able to allocate our own "struct address_space" to control @@ -825,7 +812,7 @@ void drm_dev_unregister(struct drm_device *dev) drm_lastclose(dev); dev->registered = false; - drm_unplug_dev(dev); + drm_device_set_plug_state(dev, false); if (drm_core_check_feature(dev, DRIVER_MODESET)) drm_modeset_unregister_all(dev); diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index 0fefc3f..eb63078 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -544,7 +544,6 @@ void drm_dev_unregister(struct drm_device *dev); void drm_dev_ref(struct drm_device *dev); void drm_dev_unref(struct drm_device *dev); void drm_put_dev(struct drm_device *dev); -void drm_unplug_dev(struct drm_device *dev); int drm_dev_set_unique(struct drm_device *dev, const char *name); -- 2.1.4