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author | Noralf Trønnes <noralf@tronnes.org> | 2019-02-08 17:01:02 +0300 |
---|---|---|
committer | Dave Airlie <airlied@redhat.com> | 2019-03-25 08:58:05 +0300 |
commit | 3f04e0a6cfebf48152ac64502346cdc258811f79 (patch) | |
tree | 4ccc47708c31d7198068575adf781b581eb00d91 /drivers/gpu/drm/drm_drv.c | |
parent | b23b52b6720e4be1652a4c92819f34d91e735559 (diff) | |
download | linux-3f04e0a6cfebf48152ac64502346cdc258811f79.tar.xz |
drm: Fix drm_release() and device unplug
If userspace has open fd(s) when drm_dev_unplug() is run, it will result
in drm_dev_unregister() being called twice. First in drm_dev_unplug() and
then later in drm_release() through the call to drm_put_dev().
Since userspace already holds a ref on drm_device through the drm_minor,
it's not necessary to add extra ref counting based on no open file
handles. Instead just drm_dev_put() unconditionally in drm_dev_unplug().
We now have this:
- Userpace holds a ref on drm_device as long as there's open fd(s)
- The driver holds a ref on drm_device as long as it's bound to the
struct device
When both sides are done with drm_device, it is released.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sean Paul <sean@poorly.run>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190208140103.28919-2-noralf@tronnes.org
Diffstat (limited to 'drivers/gpu/drm/drm_drv.c')
-rw-r--r-- | drivers/gpu/drm/drm_drv.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 381581b01d48..05bbc2b622fc 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -376,11 +376,7 @@ void drm_dev_unplug(struct drm_device *dev) synchronize_srcu(&drm_unplug_srcu); drm_dev_unregister(dev); - - mutex_lock(&drm_global_mutex); - if (dev->open_count == 0) - drm_dev_put(dev); - mutex_unlock(&drm_global_mutex); + drm_dev_put(dev); } EXPORT_SYMBOL(drm_dev_unplug); |