From: Daniel Vetter <daniel@ffwll.ch>
To: Jeffy Chen <jeffy.chen@rock-chips.com>
Cc: linux-kernel@vger.kernel.org, Dave Airlie <airlied@redhat.com>,
briannorris@chromium.org, dianders@chromium.org,
tfiga@chromium.org, dri-devel@lists.freedesktop.org,
Daniel Vetter <daniel.vetter@intel.com>,
zyw@rock-chips.com, marcheu@chromium.org, hshi@chromium.org
Subject: Re: [PATCH v7 1/2] drm: Unplug drm device when unregistering it
Date: Wed, 12 Apr 2017 08:33:18 +0200 [thread overview]
Message-ID: <20170412063318.mzijyktw6kp7e4uo@phenom.ffwll.local> (raw)
In-Reply-To: <1491881502-24357-2-git-send-email-jeffy.chen@rock-chips.com>
On Tue, Apr 11, 2017 at 11:31:41AM +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.
>
> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> Reviewed-by: Sean Paul <seanpaul@chromium.org>
>
> ---
>
> Changes in v7:
> Address Sean Paul <seanpaul@chromium.org>'s comments.
>
> Changes in v6:
> Address Daniel Vetter <daniel@ffwll.ch>'s comments.
Please don't just list the names, but what you've changed. As-is this
isn't very informative ... Also, in drm we prefer the patch changelog
above the --- line, for more credit to the review process.
A few questions below.
-Daniel
>
> Changes in v5:
> Fix wrong git account.
>
> Changes in v2:
> Fix some commit messages.
>
> drivers/gpu/drm/drm_drv.c | 8 ++++----
> drivers/gpu/drm/udl/udl_drv.c | 2 +-
> include/drm/drmP.h | 5 +++--
> 3 files changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index b5c6bb4..ad13e20 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -357,12 +357,9 @@ EXPORT_SYMBOL(drm_put_dev);
>
> void drm_unplug_dev(struct drm_device *dev)
I think this function can now be unexported and made static?
> {
> - /* for a USB device */
> - drm_dev_unregister(dev);
> -
> mutex_lock(&drm_global_mutex);
>
> - drm_device_set_unplugged(dev);
> + drm_device_set_plug_state(dev, false);
>
> if (dev->open_count == 0) {
> drm_put_dev(dev);
> @@ -787,6 +784,8 @@ 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 +825,7 @@ void drm_dev_unregister(struct drm_device *dev)
> drm_lastclose(dev);
>
> dev->registered = false;
> + drm_unplug_dev(dev);
>
> 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)
Why this change here? I thought the plan was to just unplug _all_ devices
at unregister time? Also, I think we want to make this into a static
function in drm_drv.c
> {
> smp_wmb();
> - atomic_set(&dev->unplugged, 1);
> + atomic_set(&dev->unplugged, !plugged);
> }
>
> static inline int drm_device_is_unplugged(struct drm_device *dev)
> --
> 2.1.4
>
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2017-04-12 6:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-11 3:31 [PATCH v7 0/2] drm: rockchip: Fix rockchip drm unbind crash error Jeffy Chen
2017-04-11 3:31 ` [PATCH v7 1/2] drm: Unplug drm device when unregistering it Jeffy Chen
2017-04-12 6:33 ` Daniel Vetter [this message]
2017-04-12 8:17 ` jeffy
2017-04-12 8:44 ` jeffy
2017-04-11 3:31 ` [PATCH v7 2/2] drm: Prevent release fb after cleanup drm_mode_config Jeffy Chen
2017-04-12 6:36 ` Daniel Vetter
2017-04-12 8:39 ` jeffy
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