drm: Introduce drm_connector_register_all() helper

As a pair to already existing drm_connector_unplug_all()
(which we'll rename in this series to drm_connector_unregister_all()) we're adding generic implementation of what is already done in some drivers for registering all connectors.

After implementation of that new helper we're updating 2 drivers that used to use it's own implementation:
[1] atmel_hlcdc
[2] rcar_du

Other drivers still use load() callback and so should be first modified so their load() gets called from their probe() explicitly.

Build- and run-tested on yet to be upstreamed ARC PGU (part of AXS10x board).

Changes v4 -> v5:
* Added missing mutex unlock on a fail path in drm_connector_register_all() Thanks David for his attention and patience!

Changes v3 -> v4:
* Based on current drm-intel/topic/drm-misc
It's now on commit 6c87e5c3ec6db052f3744804a517b6fb003906e1 And since thet new base already has
"drm: Rename drm_connector_unplug_all() to drm_connector_unregister_all()" this series now only includes 3 subsequent patches.

* In drm_connector_register_all() fail path which calls unregister_all() is moved outside of loop&locked section (as suggested by Daniel)

Changes v2 -> v3:
* Added acks for 1, 3 and 4 patches
* Updated kerneldoc descriptins of both register_ and unregister_all()
* Updated commit messages (mostly spellos and grammar issues)

Changes v1 -> v2:
* Rename drm_connector_unplug_all() to drm_connector_unregister_all()
* Use drm_for_each_connector() instead of list_for_each_entry()
* Updated kerneldoc for drm_dev_register()

Alexey Brodkin (3):
drm: Introduce drm_connector_register_all() helper
drm: atmel_hldc: Use generic drm_connector_register_all() helper
drm: rcar-du: Use generic drm_connector_register_all() helper

 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 39 ++-------------------------
 drivers/gpu/drm/drm_crtc.c                   | 40 ++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_drv.c                    |  6 ++++-
 drivers/gpu/drm/rcar-du/rcar_du_drv.c        |  9 +------
 include/drm/drm_crtc.h                       |  3 ++-
 5 files changed, 50 insertions(+), 47 deletions(-)

2.5.0

As a pair to already existing drm_connector_unregister_all() we're adding generic implementation of what is already done in some drivers.

Once this helper is implemented we'll be ready to switch existing driver-specific implementations with the generic one.

---

Changes v4 -> v5:
* Added missing mutex unlock on a fail path in drm_connector_register_all(). Thanks David for his attention and patience!

Changes v3 -> v4:
* In drm_connector_register_all() fail path which calls unregister_all() is moved outside of loop&locked section (as suggested by Daniel)

Changes v2 -> v3:
* Updated title with capital after colon
* Simplified failure path with direct and unconditional invocation of unregister_all()
* Updated kerneldoc description of the drm_connector_register_all()

Changes v1 -> v2:
* Rename drm_connector_unplug_all() to drm_connector_unregister_all()
* Use drm_for_each_connector() instead of list_for_each_entry()
* Updated kerneldoc for drm_dev_register()

 drivers/gpu/drm/drm_crtc.c | 40 ++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_drv.c  |  6 +++++-
 include/drm/drm_crtc.h     |  3 ++-
 3 files changed, 47 insertions(+), 2 deletions(-)

index 7675826..af6e7ae 100644
@@ -1079,6 +1079,46 @@ void drm_connector_unregister(struct drm_connector *connector)
 EXPORT_SYMBOL(drm_connector_unregister);
 
 /**
+ * drm_connector_register_all - register all connectors
+ * @dev: drm device
+ *
+ * This function registers all connectors in sysfs and other places so that
+ * userspace can start to access them. Drivers can call it after calling
+ * drm_dev_register() to complete the device registration, if they don't call
+ * drm_connector_register() on each connector individually.
+ *
+ * When a device is unplugged and should be removed from userspace access,
+ * call drm_connector_unregister_all(), which is the inverse of this
+ * function.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int drm_connector_register_all(struct drm_device *dev)
+{
+	struct drm_connector *connector;
+	int ret;
+
+	mutex_lock(&dev->mode_config.mutex);
+
+	drm_for_each_connector(connector, dev) {
+		ret = drm_connector_register(connector);
+		if (ret)
+			goto err;
+	}
+
+	mutex_unlock(&dev->mode_config.mutex);
+
+	return 0;
+
+err:
+	mutex_unlock(&dev->mode_config.mutex);
+	drm_connector_unregister_all(dev);
+	return ret;
+}
+EXPORT_SYMBOL(drm_connector_register_all);
+
+/**
  * drm_connector_unregister_all - unregister connector userspace interfaces
  * @dev: drm device
  *

index 167c8d3..2c9a2b6 100644
@@ -715,7 +715,11 @@ EXPORT_SYMBOL(drm_dev_unref);
  *
  * Register the DRM device @dev with the system, advertise device to user-space
  * and start normal device operation. @dev must be allocated via drm_dev_alloc()
- * previously.
+ * previously. Right after drm_dev_register() the driver should call
+ * drm_connector_register_all() to register all connectors in sysfs. This is
+ * a separate call for backward compatibility with drivers still using
+ * the deprecated ->load() callback, where connectors are registered from within
+ * the ->load() callback.
  *
  * Never call this twice on any device!
  *

index 12f2bd4..6231f6c 100644
@@ -2253,7 +2253,8 @@ void drm_connector_unregister(struct drm_connector *connector);
 
 extern void drm_connector_cleanup(struct drm_connector *connector);
 extern unsigned int drm_connector_index(struct drm_connector *connector);
-/* helper to unregister all connectors from sysfs for device */
+/* helpers to {un}register all connectors from sysfs for device */
+extern int drm_connector_register_all(struct drm_device *dev);
 extern void drm_connector_unregister_all(struct drm_device *dev);
 
 extern int drm_bridge_add(struct drm_bridge *bridge);

2.5.0

This driver used to have its own implementation of connector_register_all() which actually was taken as a prototype of drm_connector_register_all().

Now when drm_connector_register_all() exists reusing it here.

And while at it replace atmel_hlcdc_dc_connector_unplug_all() with generic drm_connector_unregister_all().

---

No changes v4 -> v5.

No changes v3 -> v4.

Changes v2 -> v3:
* Updated title with capital after colon
* Added ack from Boris

No changes v1 -> v2.

 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 39 ++--------------------------
 1 file changed, 2 insertions(+), 37 deletions(-)

index 3d8d164..1c537e4 100644
@@ -584,41 +584,6 @@ static void atmel_hlcdc_dc_unload(struct drm_device *dev)
 	destroy_workqueue(dc->wq);
 }
 
-static int atmel_hlcdc_dc_connector_plug_all(struct drm_device *dev)
-{
-	struct drm_connector *connector, *failed;
-	int ret;
-
-	mutex_lock(&dev->mode_config.mutex);
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-		ret = drm_connector_register(connector);
-		if (ret) {
-			failed = connector;
-			goto err;
-		}
-	}
-	mutex_unlock(&dev->mode_config.mutex);
-	return 0;
-
-err:
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-		if (failed == connector)
-			break;
-
-		drm_connector_unregister(connector);
-	}
-	mutex_unlock(&dev->mode_config.mutex);
-
-	return ret;
-}
-
-static void atmel_hlcdc_dc_connector_unplug_all(struct drm_device *dev)
-{
-	mutex_lock(&dev->mode_config.mutex);
-	drm_connector_unplug_all(dev);
-	mutex_unlock(&dev->mode_config.mutex);
-}
-
 static void atmel_hlcdc_dc_lastclose(struct drm_device *dev)
 {
 	struct atmel_hlcdc_dc *dc = dev->dev_private;

@@ -736,7 +701,7 @@ static int atmel_hlcdc_dc_drm_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_unload;
 
-	ret = atmel_hlcdc_dc_connector_plug_all(ddev);
+	ret = drm_connector_register_all(ddev);
 	if (ret)
 		goto err_unregister;
 

@@ -758,7 +723,7 @@ static int atmel_hlcdc_dc_drm_remove(struct platform_device *pdev)
 {
 	struct drm_device *ddev = platform_get_drvdata(pdev);
 
-	atmel_hlcdc_dc_connector_unplug_all(ddev);
+	drm_connector_unregister_all(ddev);
 	drm_dev_unregister(ddev);
 	atmel_hlcdc_dc_unload(ddev);
 	drm_dev_unref(ddev);

2.5.0

Now that a generic drm_connector_register_all() helper exists we may safely substitute it for the driver-specific implementation of connectors plugging in sysfs.

---

No changes v4 -> v5.

No changes v3 -> v4.

Changes v2 -> v3:
* Updated title with capital after colon
* Updated commit message with fixes of spellos and grammar issues
* Added ack from Laurent

No changes v1 -> v2.

 drivers/gpu/drm/rcar-du/rcar_du_drv.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

index 644db36..0f251dc 100644
@@ -361,14 +361,7 @@ static int rcar_du_probe(struct platform_device *pdev)
 	if (ret)
 		goto error;
 
-	mutex_lock(&ddev->mode_config.mutex);
-	drm_for_each_connector(connector, ddev) {
-		ret = drm_connector_register(connector);
-		if (ret < 0)
-			break;
-	}
-	mutex_unlock(&ddev->mode_config.mutex);
-
+	ret = drm_connector_register_all(ddev);
 	if (ret < 0)
 		goto error;
 

2.5.0

Hi Alexey,

Next time, can you please send all the patches of the series, not only the cover letter.

Thanks,

Boris

Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Hi Boris,

Sure.

It would be so much more convenient if git may add all people mentioned in any patch of series to Cc list for all other patches (+- cover letter). Without that feature one has to add all people in Cc explicitly in each patch.

-Alexey