[PATCH 0/3 v4] drm: Introduce drm_connector_register_all() helper

[PATCH 0/3 v4] 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

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 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

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
Cc: David Herrmann <dh.herrmann@gmail.com>

 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 39 ++--------------------------
 drivers/gpu/drm/drm_crtc.c                   | 39 ++++++++++++++++++++++++++++
 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, 49 insertions(+), 47 deletions(-)

-- 
2.5.0

[PATCH 1/3 v4] 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>
Cc: David Herrmann <dh.herrmann@gmail.com>
---

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 | 39 +++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_drv.c  |  6 +++++-
 include/drm/drm_crtc.h     |  3 ++-
 3 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 7675826..3e4cdb1 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1079,6 +1079,45 @@ 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:
+	drm_connector_unregister_all(dev);
+	return ret;
+}
+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 12f2bd4..6231f6c 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -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

[PATCH 2/3 v4] 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>
---

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(-)

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 3/3 v4] 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>
---

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(-)

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 1/3 v4] drm: Introduce drm_connector_register_all() helper

[David Herrmann]

Hi

On Tue, Mar 29, 2016 at 12:02 PM, 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>
> Cc: David Herrmann <dh.herrmann@gmail.com>
> ---
>
> 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 | 39 +++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_drv.c  |  6 +++++-
>  include/drm/drm_crtc.h     |  3 ++-
>  3 files changed, 46 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 7675826..3e4cdb1 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -1079,6 +1079,45 @@ 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:
> +       drm_connector_unregister_all(dev);

You _must_ unlock the mutex before returning.

Thanks
David

> +       return ret;
> +}
> +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 12f2bd4..6231f6c 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -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
>

Re: [PATCH 1/3 v4] drm: Introduce drm_connector_register_all() helper

[Alexey Brodkin]

Hi David,

On Tue, 2016-03-29 at 12:08 +0200, David Herrmann wrote:
> Hi
> 
> On Tue, Mar 29, 2016 at 12:02 PM, 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>
> > Cc: David Herrmann <dh.herrmann@gmail.com>
> > ---
> > 
> > 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 | 39 +++++++++++++++++++++++++++++++++++++++
> >  drivers/gpu/drm/drm_drv.c  |  6 +++++-
> >  include/drm/drm_crtc.h     |  3 ++-
> >  3 files changed, 46 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> > index 7675826..3e4cdb1 100644
> > --- a/drivers/gpu/drm/drm_crtc.c
> > +++ b/drivers/gpu/drm/drm_crtc.c
> > @@ -1079,6 +1079,45 @@ 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:
> > +       drm_connector_unregister_all(dev);
> You _must_ unlock the mutex before returning.

So true!

BTW that's why I liked the previous solution - code was much cleaner
with only 1 branch of execution.

Will resend v5 in a minute.

-Alexey