Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936704AbdDZUgV (ORCPT ); Wed, 26 Apr 2017 16:36:21 -0400 Received: from mail-qk0-f169.google.com ([209.85.220.169]:33968 "EHLO mail-qk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753771AbdDZUgN (ORCPT ); Wed, 26 Apr 2017 16:36:13 -0400 Date: Wed, 26 Apr 2017 16:36:09 -0400 From: Sean Paul To: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Cc: Jeffy Chen , linux-kernel@vger.kernel.org, Dave Airlie , briannorris@chromium.org, dianders@chromium.org, tfiga@chromium.org, dri-devel@lists.freedesktop.org, Daniel Vetter , zyw@rock-chips.com, marcheu@chromium.org, hshi@chromium.org Subject: Re: [PATCH v8 1/2] drm: Unplug drm device when unregistering it Message-ID: <20170426203609.2ezdzad54rgnotnr@art_vandelay> References: <1491965730-31393-1-git-send-email-jeffy.chen@rock-chips.com> <1491965730-31393-2-git-send-email-jeffy.chen@rock-chips.com> <20170426194331.GJ30290@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170426194331.GJ30290@intel.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: 4934 Lines: 153 On Wed, Apr 26, 2017 at 10:43:31PM +0300, Ville Syrj?l? wrote: > On Wed, Apr 12, 2017 at 10:55:29AM +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 > > Reviewed-by: Sean Paul > > > > --- > > > > Changes in v8: > > Fix hang when unregistering drm dev with open_count 0 > > > > Changes in v7: > > Address Sean Paul 's comments. > > > > Changes in v6: > > Address Daniel Vetter 's comments. > > > > Changes in v5: > > Fix wrong git account. > > > > Changes in v2: > > Fix some commit messages. > > > > drivers/gpu/drm/drm_drv.c | 19 +++---------------- > > drivers/gpu/drm/udl/udl_drv.c | 2 +- > > include/drm/drmP.h | 5 +++-- > > include/drm/drm_drv.h | 1 - > > 4 files changed, 7 insertions(+), 20 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > > index b5c6bb4..cc2d018 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 > > @@ -787,6 +771,8 @@ 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); > > This makes me think this has something to do with actual plugs, be > they the bath tub kind or some *ahem* other kind. > > /methinks this should at least be called set_plugged_state or > something like that. Or maybe there's an even better name that > could be used? thanks for reviewing this, Ville. fwiw, we decided this patch wasn't worth carrying upstream (see my response to v11 in <20170414151503.lmpp3udfuycavfki@art_vandelay>). Sean > > > + > > ret = 0; > > > > DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n", > > @@ -826,6 +812,7 @@ 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); > > } > > > > /* > > diff --git a/include/drm/drmP.h b/include/drm/drmP.h > > index 3bfafcd..a9a5a64 100644 > > --- a/include/drm/drmP.h > > +++ b/include/drm/drmP.h > > @@ -488,10 +488,11 @@ 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) > > +static inline void drm_device_set_plug_state(struct drm_device *dev, > > + bool plugged) > > { > > smp_wmb(); > > - atomic_set(&dev->unplugged, 1); > > + atomic_set(&dev->unplugged, !plugged); > > } > > > > static inline int drm_device_is_unplugged(struct drm_device *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 > > > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > > -- > Ville Syrj?l? > Intel OTC -- Sean Paul, Software Engineer, Google / Chromium OS