On 2/3/19 5:41 PM, Noralf Trønnes wrote: > The only thing now that makes drm_dev_unplug() special is that it sets > drm_device->unplugged. Move this code to drm_dev_unregister() so that we > can remove drm_dev_unplug(). > > Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > --- > > Maybe s/unplugged/unregistered/ ? > > I looked at drm_device->registered, but using that would mean that > drm_dev_is_unplugged() would return before drm_device is registered. > And given that its current purpose is to prevent race against connector > registration, I stayed away from it. > > Noralf. > > > drivers/gpu/drm/drm_drv.c | 27 +++++++++++++++------------ > include/drm/drm_drv.h | 10 ++++------ > 2 files changed, 19 insertions(+), 18 deletions(-) > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > index 05bbc2b622fc..e0941200edc6 100644 > --- a/drivers/gpu/drm/drm_drv.c > +++ b/drivers/gpu/drm/drm_drv.c > @@ -366,15 +366,6 @@ EXPORT_SYMBOL(drm_dev_exit); > */ > void drm_dev_unplug(struct drm_device *dev) > { > - /* > - * After synchronizing any critical read section is guaranteed to see > - * the new value of ->unplugged, and any critical section which might > - * still have seen the old value of ->unplugged is guaranteed to have > - * finished. > - */ > - dev->unplugged = true; > - synchronize_srcu(&drm_unplug_srcu); > - > drm_dev_unregister(dev); > drm_dev_put(dev); > } > @@ -832,11 +823,14 @@ EXPORT_SYMBOL(drm_dev_register); > * drm_dev_register() but does not deallocate the device. The caller must call > * drm_dev_put() to drop their final reference. > * > - * A special form of unregistering for hotpluggable devices is drm_dev_unplug(), > - * which can be called while there are still open users of @dev. > + * This function can be called while there are still open users of @dev as long > + * as the driver protects its device resources using drm_dev_enter() and > + * drm_dev_exit(). > * > * This should be called first in the device teardown code to make sure > - * userspace can't access the device instance any more. > + * userspace can't access the device instance any more. Drivers that support > + * device unplug will probably want to call drm_atomic_helper_shutdown() first > + * in order to disable the hardware on regular driver module unload. > */ > void drm_dev_unregister(struct drm_device *dev) > { > @@ -845,6 +839,15 @@ void drm_dev_unregister(struct drm_device *dev) > if (drm_core_check_feature(dev, DRIVER_LEGACY)) > drm_lastclose(dev); > > + /* > + * After synchronizing any critical read section is guaranteed to see > + * the new value of ->unplugged, and any critical section which might > + * still have seen the old value of ->unplugged is guaranteed to have > + * finished. > + */ > + dev->unplugged = true; > + synchronize_srcu(&drm_unplug_srcu); > + > dev->registered = false; > > drm_client_dev_unregister(dev); > diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h > index ca46a45a9cce..c50696c82a42 100644 > --- a/include/drm/drm_drv.h > +++ b/include/drm/drm_drv.h > @@ -736,13 +736,11 @@ void drm_dev_unplug(struct drm_device *dev); > * drm_dev_is_unplugged - is a DRM device unplugged > * @dev: DRM device > * > - * This function can be called to check whether a hotpluggable is unplugged. > - * Unplugging itself is singalled through drm_dev_unplug(). If a device is > - * unplugged, these two functions guarantee that any store before calling > - * drm_dev_unplug() is visible to callers of this function after it completes > + * This function can be called to check whether @dev is unregistered. This can > + * be used to detect that the underlying parent device is gone. > * > - * WARNING: This function fundamentally races against drm_dev_unplug(). It is > - * recommended that drivers instead use the underlying drm_dev_enter() and > + * WARNING: This function fundamentally races against drm_dev_unregister(). It > + * is recommended that drivers instead use the underlying drm_dev_enter() and > * drm_dev_exit() function pairs. > */ > static inline bool drm_dev_is_unplugged(struct drm_device *dev) _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx