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>
---
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)
--
2.20.1
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