Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753542AbdDKVFJ (ORCPT ); Tue, 11 Apr 2017 17:05:09 -0400 Received: from mail-io0-f177.google.com ([209.85.223.177]:34825 "EHLO mail-io0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751879AbdDKVFG (ORCPT ); Tue, 11 Apr 2017 17:05:06 -0400 Date: Tue, 11 Apr 2017 17:05:03 -0400 From: Sean Paul To: Jeffy Chen Cc: linux-kernel@vger.kernel.org, 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, Daniel Vetter , Jani Nikula , dri-devel@lists.freedesktop.org, David Airlie Subject: Re: [PATCH] drm: Fixup hang when unregistering drm dev with open_count 0 Message-ID: <20170411210503.l3fcubrrbvpdwbkk@art_vandelay> References: <1491944274-29007-1-git-send-email-jeffy.chen@rock-chips.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1491944274-29007-1-git-send-email-jeffy.chen@rock-chips.com> User-Agent: NeoMutt/20170306-66-6ddb52-dirty (1.8.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2275 Lines: 79 On Wed, Apr 12, 2017 at 04:57:54AM +0800, Jeffy Chen wrote: > 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. Hi Jeffy, That patch was not applied anywhere, the test robot just picked it up from the mailing list. Please squash this into the original patch and re-send. Thanks, Sean > > 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 > -- Sean Paul, Software Engineer, Google / Chromium OS