Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754585AbdDLPD2 (ORCPT ); Wed, 12 Apr 2017 11:03:28 -0400 Received: from mail-qt0-f172.google.com ([209.85.216.172]:36473 "EHLO mail-qt0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753254AbdDLPDY (ORCPT ); Wed, 12 Apr 2017 11:03:24 -0400 Date: Wed, 12 Apr 2017 11:03:21 -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, Chris Wilson , David Airlie , Tom Gundersen , Dave Airlie Subject: Re: [PATCH v9] drm: Unplug drm device when unregistering it Message-ID: <20170412150321.uqlbrkb55chajylq@art_vandelay> References: <1491987381-32533-1-git-send-email-jeffy.chen@rock-chips.com> <1491987381-32533-2-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: <1491987381-32533-2-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: 4523 Lines: 156 On Wed, Apr 12, 2017 at 04:56:21PM +0800, Jeffy Chen wrote: > After unbinding drm, the user space may still owns the drm dev fd, and > may still be able to call drm ioctl. > > We're using an unplugged state to prevent something like that, so let's > reuse it here. > > Also drop drm_unplug_dev, because it would be unused after other changes. > > Signed-off-by: Jeffy Chen > > Changes in v9: > Move drm_device_set_plug_state into drm_drv.c . > > Changes in v8: > Fix hang when unregistering drm dev with open_count 0. > > Changes in v7: > Add drm_device_set_plug_state helper. > > Changes in v6: > Reuse unplug status. > > Changes in v5: > Fix wrong git account. > > Changes in v2: > Fix some commit messages. > Hi Jeffy, A couple bookkeeping notes: - Please end the commit message with your Signed-off-by tag - No need to send cover letters for one patch. All info should be in the commit message. Include superfluous information (such as tested on 4.4 kernel) after --- > --- > drivers/gpu/drm/drm_drv.c | 26 ++++++++++---------------- > drivers/gpu/drm/udl/udl_drv.c | 2 +- > include/drm/drmP.h | 6 ------ > include/drm/drm_drv.h | 1 - > 4 files changed, 11 insertions(+), 24 deletions(-) > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > index b5c6bb4..e1da4d1 100644 > --- a/drivers/gpu/drm/drm_drv.c > +++ b/drivers/gpu/drm/drm_drv.c > @@ -355,22 +355,6 @@ void drm_put_dev(struct drm_device *dev) > } > EXPORT_SYMBOL(drm_put_dev); > > -void drm_unplug_dev(struct drm_device *dev) > -{ > - /* for a USB device */ > - drm_dev_unregister(dev); > - > - mutex_lock(&drm_global_mutex); > - > - drm_device_set_unplugged(dev); > - > - 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 > @@ -733,6 +717,13 @@ static void remove_compat_control_link(struct drm_device *dev) > kfree(name); > } > > +static inline void drm_device_set_plug_state(struct drm_device *dev, > + bool plugged) > +{ > + smp_wmb(); > + atomic_set(&dev->unplugged, !plugged); > +} > + > /** > * drm_dev_register - Register DRM device > * @dev: Device to register > @@ -787,6 +778,8 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags) > if (drm_core_check_feature(dev, DRIVER_MODESET)) > drm_modeset_register_all(dev); > > + drm_device_set_plug_state(dev, true); > + > ret = 0; > > DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n", > @@ -826,6 +819,7 @@ void drm_dev_unregister(struct drm_device *dev) > drm_lastclose(dev); > > dev->registered = false; > + drm_device_set_plug_state(dev, false); > > if (drm_core_check_feature(dev, DRIVER_MODESET)) > drm_modeset_unregister_all(dev); > diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c > index cd8b017..5dbd916 100644 > --- a/drivers/gpu/drm/udl/udl_drv.c > +++ b/drivers/gpu/drm/udl/udl_drv.c > @@ -108,7 +108,7 @@ static void udl_usb_disconnect(struct usb_interface *interface) > drm_kms_helper_poll_disable(dev); > udl_fbdev_unplug(dev); > udl_drop_usb(dev); > - drm_unplug_dev(dev); > + drm_dev_unregister(dev); I think you need drm_dev_unref here as well. Sean > } > > /* > diff --git a/include/drm/drmP.h b/include/drm/drmP.h > index 3bfafcd..980a204 100644 > --- a/include/drm/drmP.h > +++ b/include/drm/drmP.h > @@ -488,12 +488,6 @@ static __inline__ int drm_core_check_feature(struct drm_device *dev, > return ((dev->driver->driver_features & feature) ? 1 : 0); > } > > -static inline void drm_device_set_unplugged(struct drm_device *dev) > -{ > - smp_wmb(); > - atomic_set(&dev->unplugged, 1); > -} > - > static inline int drm_device_is_unplugged(struct drm_device *dev) > { > int ret = atomic_read(&dev->unplugged); > 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