[PATCH 0/4 v3] drm: Introduce drm_connector_register_all() helper

[PATCH 0/4 v3] drm: Introduce drm_connector_register_all() helper

[Alexey Brodkin]

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

And one driver that uses unregister():
 [1] udl

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 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 (4):
  drm: Rename drm_connector_unplug_all() to
    drm_connector_unregister_all()
  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                   | 59 ++++++++++++++++++++++++----
 drivers/gpu/drm/drm_drv.c                    |  6 ++-
 drivers/gpu/drm/rcar-du/rcar_du_drv.c        | 14 +------
 drivers/gpu/drm/udl/udl_drv.c                |  2 +-
 include/drm/drm_crtc.h                       |  5 ++-
 6 files changed, 64 insertions(+), 61 deletions(-)

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linux-renesas-soc@vger.kernel.org
-- 
2.5.0

[PATCH 1/4 v3] drm: Rename drm_connector_unplug_all() to drm_connector_unregister_all()

[Alexey Brodkin]

Current name is a bit misleading because what that helper function
really does it calls drm_connector_unregister() for all connectors.

This all has nothing to do with hotplugging so let's name things
properly.

And while at it remove potentially dangerous locking around
drm_connector_unregister() in rcar_du_remove() as mentioned
in kerneldoc for drm_connector_unregister_all().

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: linux-renesas-soc@vger.kernel.org
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

Changes v2 -> v3:
 * Updated title with capital after colon
 * Updated kerneldoc description of drm_connector_unregister_all()
   so that it will match description of register_all() to be introduced
   in the next change
 * Added ack from Laurent

Changes v1 -> v2:
 * This patch was only introduced in v2.

 drivers/gpu/drm/drm_crtc.c            | 18 +++++++++---------
 drivers/gpu/drm/rcar-du/rcar_du_drv.c |  5 +----
 drivers/gpu/drm/udl/udl_drv.c         |  2 +-
 include/drm/drm_crtc.h                |  4 ++--
 4 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 65258ac..65488a6 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1080,25 +1080,25 @@ void drm_connector_unregister(struct drm_connector *connector)
 }
 EXPORT_SYMBOL(drm_connector_unregister);
 
-
 /**
- * drm_connector_unplug_all - unregister connector userspace interfaces
+ * drm_connector_unregister_all - unregister connector userspace interfaces
  * @dev: drm device
  *
- * This function unregisters all connector userspace interfaces in sysfs. Should
- * be call when the device is disconnected, e.g. from an usb driver's
- * ->disconnect callback.
+ * This functions unregisters all connectors from sysfs and other places so
+ * that userspace can no longer access them. Drivers should call this as the
+ * first step tearing down the device instace, or when the underlying
+ * physical device disappeared (e.g. USB unplug), right before calling
+ * drm_dev_unregister().
  */
-void drm_connector_unplug_all(struct drm_device *dev)
+void drm_connector_unregister_all(struct drm_device *dev)
 {
 	struct drm_connector *connector;
 
 	/* FIXME: taking the mode config mutex ends up in a clash with sysfs */
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
+	drm_for_each_connector(connector, dev)
 		drm_connector_unregister(connector);
-
 }
-EXPORT_SYMBOL(drm_connector_unplug_all);
+EXPORT_SYMBOL(drm_connector_unregister_all);
 
 /**
  * drm_encoder_init - Init a preallocated encoder
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index ed6006b..644db36 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -278,10 +278,7 @@ static int rcar_du_remove(struct platform_device *pdev)
 	struct rcar_du_device *rcdu = platform_get_drvdata(pdev);
 	struct drm_device *ddev = rcdu->ddev;
 
-	mutex_lock(&ddev->mode_config.mutex);
-	drm_connector_unplug_all(ddev);
-	mutex_unlock(&ddev->mode_config.mutex);
-
+	drm_connector_unregister_all(ddev);
 	drm_dev_unregister(ddev);
 
 	if (rcdu->fbdev)
diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c
index 772ec9e..c204089 100644
--- a/drivers/gpu/drm/udl/udl_drv.c
+++ b/drivers/gpu/drm/udl/udl_drv.c
@@ -94,7 +94,7 @@ static void udl_usb_disconnect(struct usb_interface *interface)
 	struct drm_device *dev = usb_get_intfdata(interface);
 
 	drm_kms_helper_poll_disable(dev);
-	drm_connector_unplug_all(dev);
+	drm_connector_unregister_all(dev);
 	udl_fbdev_unplug(dev);
 	udl_drop_usb(dev);
 	drm_unplug_dev(dev);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 8c7fb3d..42d9f4d 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -2214,8 +2214,8 @@ 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 unplug all connectors from sysfs for device */
-extern void drm_connector_unplug_all(struct drm_device *dev);
+/* helper to unregister all connectors from sysfs for device */
+extern void drm_connector_unregister_all(struct drm_device *dev);
 
 extern int drm_bridge_add(struct drm_bridge *bridge);
 extern void drm_bridge_remove(struct drm_bridge *bridge);
-- 
2.5.0

[PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[Alexey Brodkin]

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.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
---

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 | 43 +++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_drv.c  |  6 +++++-
 include/drm/drm_crtc.h     |  3 ++-
 3 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 65488a6..21eea11 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1081,6 +1081,49 @@ 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) {
+			/*
+			 * We may safely call unregister_all() here within
+			 * area locked with mutex because unregister_all()
+			 * doesn't use locks inside (see a comment in that
+			 * function).
+			 */
+			drm_connector_unregister_all(dev);
+			return ret;
+		}
+	}
+
+	mutex_unlock(&dev->mode_config.mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_connector_register_all);
+
+/**
  * drm_connector_unregister_all - unregister connector userspace interfaces
  * @dev: drm device
  *
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 167c8d3..2c9a2b6 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -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!
  *
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 42d9f4d..6a34117 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -2214,7 +2214,8 @@ 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

[PATCH 3/4 v3] drm: atmel_hldc: Use generic drm_connector_register_all() helper

[Alexey Brodkin]

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().

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---

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(-)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 3d8d164..1c537e4 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -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

[PATCH 4/4 v3] drm: rcar-du: Use generic drm_connector_register_all() helper

[Alexey Brodkin]

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.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: linux-renesas-soc@vger.kernel.org
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

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(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index 644db36..0f251dc 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -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

Re: [PATCH 1/4 v3] drm: Rename drm_connector_unplug_all() to drm_connector_unregister_all()

[Boris Brezillon]

On Wed, 23 Mar 2016 11:42:54 +0300
Alexey Brodkin <Alexey.Brodkin@synopsys.com> wrote:

> Current name is a bit misleading because what that helper function
> really does it calls drm_connector_unregister() for all connectors.
> 
> This all has nothing to do with hotplugging so let's name things
> properly.
> 
> And while at it remove potentially dangerous locking around
> drm_connector_unregister() in rcar_du_remove() as mentioned
> in kerneldoc for drm_connector_unregister_all().
> 
> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Boris Brezillon <boris.brezillon@free-electrons.com>

Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>

> Cc: linux-renesas-soc@vger.kernel.org
> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> 
> Changes v2 -> v3:
>  * Updated title with capital after colon
>  * Updated kerneldoc description of drm_connector_unregister_all()
>    so that it will match description of register_all() to be introduced
>    in the next change
>  * Added ack from Laurent
> 
> Changes v1 -> v2:
>  * This patch was only introduced in v2.
> 
>  drivers/gpu/drm/drm_crtc.c            | 18 +++++++++---------
>  drivers/gpu/drm/rcar-du/rcar_du_drv.c |  5 +----
>  drivers/gpu/drm/udl/udl_drv.c         |  2 +-
>  include/drm/drm_crtc.h                |  4 ++--
>  4 files changed, 13 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 65258ac..65488a6 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -1080,25 +1080,25 @@ void drm_connector_unregister(struct drm_connector *connector)
>  }
>  EXPORT_SYMBOL(drm_connector_unregister);
>  
> -
>  /**
> - * drm_connector_unplug_all - unregister connector userspace interfaces
> + * drm_connector_unregister_all - unregister connector userspace interfaces
>   * @dev: drm device
>   *
> - * This function unregisters all connector userspace interfaces in sysfs. Should
> - * be call when the device is disconnected, e.g. from an usb driver's
> - * ->disconnect callback.
> + * This functions unregisters all connectors from sysfs and other places so
> + * that userspace can no longer access them. Drivers should call this as the
> + * first step tearing down the device instace, or when the underlying
> + * physical device disappeared (e.g. USB unplug), right before calling
> + * drm_dev_unregister().
>   */
> -void drm_connector_unplug_all(struct drm_device *dev)
> +void drm_connector_unregister_all(struct drm_device *dev)
>  {
>  	struct drm_connector *connector;
>  
>  	/* FIXME: taking the mode config mutex ends up in a clash with sysfs */
> -	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
> +	drm_for_each_connector(connector, dev)
>  		drm_connector_unregister(connector);
> -
>  }
> -EXPORT_SYMBOL(drm_connector_unplug_all);
> +EXPORT_SYMBOL(drm_connector_unregister_all);
>  
>  /**
>   * drm_encoder_init - Init a preallocated encoder
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> index ed6006b..644db36 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> @@ -278,10 +278,7 @@ static int rcar_du_remove(struct platform_device *pdev)
>  	struct rcar_du_device *rcdu = platform_get_drvdata(pdev);
>  	struct drm_device *ddev = rcdu->ddev;
>  
> -	mutex_lock(&ddev->mode_config.mutex);
> -	drm_connector_unplug_all(ddev);
> -	mutex_unlock(&ddev->mode_config.mutex);
> -
> +	drm_connector_unregister_all(ddev);
>  	drm_dev_unregister(ddev);
>  
>  	if (rcdu->fbdev)
> diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c
> index 772ec9e..c204089 100644
> --- a/drivers/gpu/drm/udl/udl_drv.c
> +++ b/drivers/gpu/drm/udl/udl_drv.c
> @@ -94,7 +94,7 @@ static void udl_usb_disconnect(struct usb_interface *interface)
>  	struct drm_device *dev = usb_get_intfdata(interface);
>  
>  	drm_kms_helper_poll_disable(dev);
> -	drm_connector_unplug_all(dev);
> +	drm_connector_unregister_all(dev);
>  	udl_fbdev_unplug(dev);
>  	udl_drop_usb(dev);
>  	drm_unplug_dev(dev);
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 8c7fb3d..42d9f4d 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -2214,8 +2214,8 @@ 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 unplug all connectors from sysfs for device */
> -extern void drm_connector_unplug_all(struct drm_device *dev);
> +/* helper to unregister all connectors from sysfs for device */
> +extern void drm_connector_unregister_all(struct drm_device *dev);
>  
>  extern int drm_bridge_add(struct drm_bridge *bridge);
>  extern void drm_bridge_remove(struct drm_bridge *bridge);



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

Re: [PATCH 0/4 v3] drm: Introduce drm_connector_register_all() helper

[Daniel Vetter]

On Wed, Mar 23, 2016 at 11:42:53AM +0300, Alexey Brodkin wrote:
> 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
> 
> And one driver that uses unregister():
>  [1] udl
> 
> 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 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 (4):
>   drm: Rename drm_connector_unplug_all() to
>     drm_connector_unregister_all()
>   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

lgtm overall, but merge window is happening so don't want to throw 4.7
patches into drm-misc. So will let these soak for a while more, please
ping me after -rc1 is out that I don't forget them.

Thanks, Daniel

> 
>  drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 39 +-----------------
>  drivers/gpu/drm/drm_crtc.c                   | 59 ++++++++++++++++++++++++----
>  drivers/gpu/drm/drm_drv.c                    |  6 ++-
>  drivers/gpu/drm/rcar-du/rcar_du_drv.c        | 14 +------
>  drivers/gpu/drm/udl/udl_drv.c                |  2 +-
>  include/drm/drm_crtc.h                       |  5 ++-
>  6 files changed, 64 insertions(+), 61 deletions(-)
> 
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: David Airlie <airlied@linux.ie>
> Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: linux-renesas-soc@vger.kernel.org
> -- 
> 2.5.0
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[David Herrmann]

Hi

On Wed, Mar 23, 2016 at 9:42 AM, Alexey Brodkin
<Alexey.Brodkin@synopsys.com> wrote:
> 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.
>
> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: David Airlie <airlied@linux.ie>
> ---
>
> 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 | 43 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_drv.c  |  6 +++++-
>  include/drm/drm_crtc.h     |  3 ++-
>  3 files changed, 50 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 65488a6..21eea11 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -1081,6 +1081,49 @@ 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) {
> +                       /*
> +                        * We may safely call unregister_all() here within
> +                        * area locked with mutex because unregister_all()
> +                        * doesn't use locks inside (see a comment in that
> +                        * function).
> +                        */

Ugh? unregister_all() says:

/* FIXME: taking the mode config mutex ends up in a clash with sysfs */

This strongly contradicts your comment. Anyway, regardless how you
want to fix it: You better unlock the mode-config mutex before
returning below.

Thanks
David

> +                       drm_connector_unregister_all(dev);
> +                       return ret;
> +               }
> +       }
> +
> +       mutex_unlock(&dev->mode_config.mutex);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL(drm_connector_register_all);
> +
> +/**
>   * drm_connector_unregister_all - unregister connector userspace interfaces
>   * @dev: drm device
>   *
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 167c8d3..2c9a2b6 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -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!
>   *
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 42d9f4d..6a34117 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -2214,7 +2214,8 @@ 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
>

Re: [PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[David Herrmann]

Hi

On Wed, Mar 23, 2016 at 9:42 AM, Alexey Brodkin
<Alexey.Brodkin@synopsys.com> wrote:
> 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.
>
> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: David Airlie <airlied@linux.ie>
> ---
>
> 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 | 43 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_drv.c  |  6 +++++-
>  include/drm/drm_crtc.h     |  3 ++-
>  3 files changed, 50 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 65488a6..21eea11 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -1081,6 +1081,49 @@ 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) {
> +                       /*
> +                        * We may safely call unregister_all() here within
> +                        * area locked with mutex because unregister_all()
> +                        * doesn't use locks inside (see a comment in that
> +                        * function).
> +                        */

Ugh? unregister_all() says:

/* FIXME: taking the mode config mutex ends up in a clash with sysfs */

This strongly contradicts your comment. Anyway, regardless how you
want to fix it: You better unlock the mode-config mutex before
returning below.

Thanks
David

> +                       drm_connector_unregister_all(dev);
> +                       return ret;
> +               }
> +       }
> +
> +       mutex_unlock(&dev->mode_config.mutex);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL(drm_connector_register_all);
> +
> +/**
>   * drm_connector_unregister_all - unregister connector userspace interfaces
>   * @dev: drm device
>   *
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 167c8d3..2c9a2b6 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -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!
>   *
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 42d9f4d..6a34117 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -2214,7 +2214,8 @@ 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
>
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[Alexey Brodkin]

Hi David,

On Wed, 2016-03-23 at 12:13 +0100, David Herrmann wrote:
> Hi
> 
> On Wed, Mar 23, 2016 at 9:42 AM, Alexey Brodkin
> <Alexey.Brodkin@synopsys.com> wrote:
> > 
> > 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.
> > 
> > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > Cc: Daniel Vetter <daniel@ffwll.ch>
> > Cc: David Airlie <airlied@linux.ie>
> > ---
> > 
> > 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 | 43 +++++++++++++++++++++++++++++++++++++++++++
> >  drivers/gpu/drm/drm_drv.c  |  6 +++++-
> >  include/drm/drm_crtc.h     |  3 ++-
> >  3 files changed, 50 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > index 65488a6..21eea11 100644
> > --- a/drivers/gpu/drm/drm_crtc.c
> > +++ b/drivers/gpu/drm/drm_crtc.c
> > @@ -1081,6 +1081,49 @@ 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) {
> > +                       /*
> > +                        * We may safely call unregister_all() here within
> > +                        * area locked with mutex because unregister_all()
> > +                        * doesn't use locks inside (see a comment in that
> > +                        * function).
> > +                        */
> Ugh? unregister_all() says:
> 
> /* FIXME: taking the mode config mutex ends up in a clash with sysfs */
> 
> This strongly contradicts your comment. Anyway, regardless how you
> want to fix it: You better unlock the mode-config mutex before
> returning below.

So good catch.
But what I really meant since we didn't get any further after registering
all "good" connections (see we're not releasing mutex still) the will be
no clashes with sysfs.

Still I;d like Daniel to comment on that separately.

-Alexey

Re: [PATCH 0/4 v3] drm: Introduce drm_connector_register_all() helper

[Alexey Brodkin]

Hi Daniel,

On Wed, 2016-03-23 at 11:37 +0100, Daniel Vetter wrote:
> On Wed, Mar 23, 2016 at 11:42:53AM +0300, Alexey Brodkin wrote:
> > 
> > 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
> > 
> > And one driver that uses unregister():
> >  [1] udl
> > 
> > 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 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 (4):
> >   drm: Rename drm_connector_unplug_all() to
> >     drm_connector_unregister_all()
> >   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
> lgtm overall, but merge window is happening so don't want to throw 4.7
> patches into drm-misc. So will let these soak for a while more, please
> ping me after -rc1 is out that I don't forget them.

As you asked I'm pinging you with request to apply that series.

Also would be very nice if you take a look at that comment from
David Herrmann before application of that series:
http://article.gmane.org/gmane.comp.video.dri.devel/149708/match=re+patch+2+4+v3+drm+introduce+drm_connector_register_al
l+helper

-Alexey

Re: [PATCH 0/4 v3] drm: Introduce drm_connector_register_all() helper

[Alexey Brodkin]

Hi Daniel,

On Wed, 2016-03-23 at 11:37 +0100, Daniel Vetter wrote:
> On Wed, Mar 23, 2016 at 11:42:53AM +0300, Alexey Brodkin wrote:
> > 
> > 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
> > 
> > And one driver that uses unregister():
> >  [1] udl
> > 
> > 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 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 (4):
> >   drm: Rename drm_connector_unplug_all() to
> >     drm_connector_unregister_all()
> >   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
> lgtm overall, but merge window is happening so don't want to throw 4.7
> patches into drm-misc. So will let these soak for a while more, please
> ping me after -rc1 is out that I don't forget them.

As you asked I'm pinging you with request to apply that series.

Also would be very nice if you take a look at that comment from
David Herrmann before application of that series:
http://article.gmane.org/gmane.comp.video.dri.devel/149708/match=re+patch+2+4+v3+drm+introduce+drm_connector_register_al
l+helper

-Alexey

Re: [PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[Daniel Vetter]

On Wed, Mar 23, 2016 at 01:41:05PM +0000, Alexey Brodkin wrote:
> Hi David,
> 
> On Wed, 2016-03-23 at 12:13 +0100, David Herrmann wrote:
> > Hi
> > 
> > On Wed, Mar 23, 2016 at 9:42 AM, Alexey Brodkin
> > <Alexey.Brodkin@synopsys.com> wrote:
> > > 
> > > 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.
> > > 
> > > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > > Cc: Daniel Vetter <daniel@ffwll.ch>
> > > Cc: David Airlie <airlied@linux.ie>
> > > ---
> > > 
> > > 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 | 43 +++++++++++++++++++++++++++++++++++++++++++
> > >  drivers/gpu/drm/drm_drv.c  |  6 +++++-
> > >  include/drm/drm_crtc.h     |  3 ++-
> > >  3 files changed, 50 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > > index 65488a6..21eea11 100644
> > > --- a/drivers/gpu/drm/drm_crtc.c
> > > +++ b/drivers/gpu/drm/drm_crtc.c
> > > @@ -1081,6 +1081,49 @@ 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) {
> > > +                       /*
> > > +                        * We may safely call unregister_all() here within
> > > +                        * area locked with mutex because unregister_all()
> > > +                        * doesn't use locks inside (see a comment in that
> > > +                        * function).
> > > +                        */
> > Ugh? unregister_all() says:
> > 
> > /* FIXME: taking the mode config mutex ends up in a clash with sysfs */
> > 
> > This strongly contradicts your comment. Anyway, regardless how you
> > want to fix it: You better unlock the mode-config mutex before
> > returning below.
> 
> So good catch.
> But what I really meant since we didn't get any further after registering
> all "good" connections (see we're not releasing mutex still) the will be
> no clashes with sysfs.
> 
> Still I;d like Daniel to comment on that separately.

I think doing the unregister_all outside of the loop&locked section is
better for future-proofing. My long-term plan for connector lifetimes and
the connector list is:
- refcounting for connectors (Dave has wip patches already).
- separate lock for the connector list (and only that).

Doing it entirely separate would make things easier and more robust.

I merged patch 1 meanwhile to drm-misc.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[Daniel Vetter]

On Wed, Mar 23, 2016 at 01:41:05PM +0000, Alexey Brodkin wrote:
> Hi David,
> 
> On Wed, 2016-03-23 at 12:13 +0100, David Herrmann wrote:
> > Hi
> > 
> > On Wed, Mar 23, 2016 at 9:42 AM, Alexey Brodkin
> > <Alexey.Brodkin@synopsys.com> wrote:
> > > 
> > > 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.
> > > 
> > > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > > Cc: Daniel Vetter <daniel@ffwll.ch>
> > > Cc: David Airlie <airlied@linux.ie>
> > > ---
> > > 
> > > 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 | 43 +++++++++++++++++++++++++++++++++++++++++++
> > >  drivers/gpu/drm/drm_drv.c  |  6 +++++-
> > >  include/drm/drm_crtc.h     |  3 ++-
> > >  3 files changed, 50 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > > index 65488a6..21eea11 100644
> > > --- a/drivers/gpu/drm/drm_crtc.c
> > > +++ b/drivers/gpu/drm/drm_crtc.c
> > > @@ -1081,6 +1081,49 @@ 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) {
> > > +                       /*
> > > +                        * We may safely call unregister_all() here within
> > > +                        * area locked with mutex because unregister_all()
> > > +                        * doesn't use locks inside (see a comment in that
> > > +                        * function).
> > > +                        */
> > Ugh? unregister_all() says:
> > 
> > /* FIXME: taking the mode config mutex ends up in a clash with sysfs */
> > 
> > This strongly contradicts your comment. Anyway, regardless how you
> > want to fix it: You better unlock the mode-config mutex before
> > returning below.
> 
> So good catch.
> But what I really meant since we didn't get any further after registering
> all "good" connections (see we're not releasing mutex still) the will be
> no clashes with sysfs.
> 
> Still I;d like Daniel to comment on that separately.

I think doing the unregister_all outside of the loop&locked section is
better for future-proofing. My long-term plan for connector lifetimes and
the connector list is:
- refcounting for connectors (Dave has wip patches already).
- separate lock for the connector list (and only that).

Doing it entirely separate would make things easier and more robust.

I merged patch 1 meanwhile to drm-misc.

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[Alexey Brodkin]

Hi Daniel,

On Tue, 2016-03-29 at 10:19 +0200, Daniel Vetter wrote:
> On Wed, Mar 23, 2016 at 01:41:05PM +0000, Alexey Brodkin wrote:
> > 
> > Hi David,
> > 
> > On Wed, 2016-03-23 at 12:13 +0100, David Herrmann wrote:
> > > 
> > > Hi
> > > 
> > > On Wed, Mar 23, 2016 at 9:42 AM, Alexey Brodkin
> > > <Alexey.Brodkin@synopsys.com> wrote:
> > > > 
> > > > 
> > > > 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.
> > > > 
> > > > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > > > Cc: Daniel Vetter <daniel@ffwll.ch>
> > > > Cc: David Airlie <airlied@linux.ie>
> > > > ---
> > > > 
> > > > 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 | 43 +++++++++++++++++++++++++++++++++++++++++++
> > > >  drivers/gpu/drm/drm_drv.c  |  6 +++++-
> > > >  include/drm/drm_crtc.h     |  3 ++-
> > > >  3 files changed, 50 insertions(+), 2 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > > > index 65488a6..21eea11 100644
> > > > --- a/drivers/gpu/drm/drm_crtc.c
> > > > +++ b/drivers/gpu/drm/drm_crtc.c
> > > > @@ -1081,6 +1081,49 @@ 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) {
> > > > +                       /*
> > > > +                        * We may safely call unregister_all() here within
> > > > +                        * area locked with mutex because unregister_all()
> > > > +                        * doesn't use locks inside (see a comment in that
> > > > +                        * function).
> > > > +                        */
> > > Ugh? unregister_all() says:
> > > 
> > > /* FIXME: taking the mode config mutex ends up in a clash with sysfs */
> > > 
> > > This strongly contradicts your comment. Anyway, regardless how you
> > > want to fix it: You better unlock the mode-config mutex before
> > > returning below.
> > So good catch.
> > But what I really meant since we didn't get any further after registering
> > all "good" connections (see we're not releasing mutex still) the will be
> > no clashes with sysfs.
> > 
> > Still I;d like Daniel to comment on that separately.
> I think doing the unregister_all outside of the loop&locked section is
> better for future-proofing. My long-term plan for connector lifetimes and
> the connector list is:
> - refcounting for connectors (Dave has wip patches already).
> - separate lock for the connector list (and only that).
> 
> Doing it entirely separate would make things easier and more robust.

Ok makes sense.

> I merged patch 1 meanwhile to drm-misc.

So may I re-send only patches 2-4 then (using "drm-misc" as a base)?

-Alexey

Re: [PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[Daniel Vetter]

On Tue, Mar 29, 2016 at 09:12:38AM +0000, Alexey Brodkin wrote:
> Hi Daniel,
> 
> On Tue, 2016-03-29 at 10:19 +0200, Daniel Vetter wrote:
> > On Wed, Mar 23, 2016 at 01:41:05PM +0000, Alexey Brodkin wrote:
> > > 
> > > Hi David,
> > > 
> > > On Wed, 2016-03-23 at 12:13 +0100, David Herrmann wrote:
> > > > 
> > > > Hi
> > > > 
> > > > On Wed, Mar 23, 2016 at 9:42 AM, Alexey Brodkin
> > > > <Alexey.Brodkin@synopsys.com> wrote:
> > > > > 
> > > > > 
> > > > > 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.
> > > > > 
> > > > > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > > > > Cc: Daniel Vetter <daniel@ffwll.ch>
> > > > > Cc: David Airlie <airlied@linux.ie>
> > > > > ---
> > > > > 
> > > > > 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 | 43 +++++++++++++++++++++++++++++++++++++++++++
> > > > >  drivers/gpu/drm/drm_drv.c  |  6 +++++-
> > > > >  include/drm/drm_crtc.h     |  3 ++-
> > > > >  3 files changed, 50 insertions(+), 2 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > > > > index 65488a6..21eea11 100644
> > > > > --- a/drivers/gpu/drm/drm_crtc.c
> > > > > +++ b/drivers/gpu/drm/drm_crtc.c
> > > > > @@ -1081,6 +1081,49 @@ 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) {
> > > > > +                       /*
> > > > > +                        * We may safely call unregister_all() here within
> > > > > +                        * area locked with mutex because unregister_all()
> > > > > +                        * doesn't use locks inside (see a comment in that
> > > > > +                        * function).
> > > > > +                        */
> > > > Ugh? unregister_all() says:
> > > > 
> > > > /* FIXME: taking the mode config mutex ends up in a clash with sysfs */
> > > > 
> > > > This strongly contradicts your comment. Anyway, regardless how you
> > > > want to fix it: You better unlock the mode-config mutex before
> > > > returning below.
> > > So good catch.
> > > But what I really meant since we didn't get any further after registering
> > > all "good" connections (see we're not releasing mutex still) the will be
> > > no clashes with sysfs.
> > > 
> > > Still I;d like Daniel to comment on that separately.
> > I think doing the unregister_all outside of the loop&locked section is
> > better for future-proofing. My long-term plan for connector lifetimes and
> > the connector list is:
> > - refcounting for connectors (Dave has wip patches already).
> > - separate lock for the connector list (and only that).
> > 
> > Doing it entirely separate would make things easier and more robust.
> 
> Ok makes sense.
> 
> > I merged patch 1 meanwhile to drm-misc.
> 
> So may I re-send only patches 2-4 then (using "drm-misc" as a base)?

Sure. drm-misc is also in linux-next, in case you need other bits to be
able to test all your patches.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 2/4 v3] drm: Introduce drm_connector_register_all() helper

[Daniel Vetter]

On Tue, Mar 29, 2016 at 09:12:38AM +0000, Alexey Brodkin wrote:
> Hi Daniel,
> 
> On Tue, 2016-03-29 at 10:19 +0200, Daniel Vetter wrote:
> > On Wed, Mar 23, 2016 at 01:41:05PM +0000, Alexey Brodkin wrote:
> > > 
> > > Hi David,
> > > 
> > > On Wed, 2016-03-23 at 12:13 +0100, David Herrmann wrote:
> > > > 
> > > > Hi
> > > > 
> > > > On Wed, Mar 23, 2016 at 9:42 AM, Alexey Brodkin
> > > > <Alexey.Brodkin@synopsys.com> wrote:
> > > > > 
> > > > > 
> > > > > 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.
> > > > > 
> > > > > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > > > > Cc: Daniel Vetter <daniel@ffwll.ch>
> > > > > Cc: David Airlie <airlied@linux.ie>
> > > > > ---
> > > > > 
> > > > > 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 | 43 +++++++++++++++++++++++++++++++++++++++++++
> > > > >  drivers/gpu/drm/drm_drv.c  |  6 +++++-
> > > > >  include/drm/drm_crtc.h     |  3 ++-
> > > > >  3 files changed, 50 insertions(+), 2 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > > > > index 65488a6..21eea11 100644
> > > > > --- a/drivers/gpu/drm/drm_crtc.c
> > > > > +++ b/drivers/gpu/drm/drm_crtc.c
> > > > > @@ -1081,6 +1081,49 @@ 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) {
> > > > > +                       /*
> > > > > +                        * We may safely call unregister_all() here within
> > > > > +                        * area locked with mutex because unregister_all()
> > > > > +                        * doesn't use locks inside (see a comment in that
> > > > > +                        * function).
> > > > > +                        */
> > > > Ugh? unregister_all() says:
> > > > 
> > > > /* FIXME: taking the mode config mutex ends up in a clash with sysfs */
> > > > 
> > > > This strongly contradicts your comment. Anyway, regardless how you
> > > > want to fix it: You better unlock the mode-config mutex before
> > > > returning below.
> > > So good catch.
> > > But what I really meant since we didn't get any further after registering
> > > all "good" connections (see we're not releasing mutex still) the will be
> > > no clashes with sysfs.
> > > 
> > > Still I;d like Daniel to comment on that separately.
> > I think doing the unregister_all outside of the loop&locked section is
> > better for future-proofing. My long-term plan for connector lifetimes and
> > the connector list is:
> > - refcounting for connectors (Dave has wip patches already).
> > - separate lock for the connector list (and only that).
> > 
> > Doing it entirely separate would make things easier and more robust.
> 
> Ok makes sense.
> 
> > I merged patch 1 meanwhile to drm-misc.
> 
> So may I re-send only patches 2-4 then (using "drm-misc" as a base)?

Sure. drm-misc is also in linux-next, in case you need other bits to be
able to test all your patches.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel