[PATCH 0/4] drm/client: Implement free callback for fbdev and log

[PATCH 0/4] drm/client: Implement free callback for fbdev and log

[Thomas Zimmermann]

Add struct drm_client_funcs.free and release the memory fbdev and
log clients from its implementations. Also fix the locking in the
log's unregister code.

Resolves several corner cases in the current clients and avoids
duplicated code.

Thomas Zimmermann (4):
  drm/client: Add client free callback to unprepare fb_helper
  drm/log: Do not hold lock across drm_client_release()
  drm/log: Add free callback
  drm/client: Do not free client memory by default

 drivers/gpu/drm/armada/armada_fbdev.c      |  2 --
 drivers/gpu/drm/clients/drm_fbdev_client.c | 17 +++++++++++++++--
 drivers/gpu/drm/clients/drm_log.c          | 16 ++++++++++++----
 drivers/gpu/drm/drm_client.c               |  4 ++++
 drivers/gpu/drm/drm_client_event.c         |  9 +++++----
 drivers/gpu/drm/drm_fbdev_dma.c            |  4 ----
 drivers/gpu/drm/drm_fbdev_shmem.c          |  2 --
 drivers/gpu/drm/drm_fbdev_ttm.c            |  2 --
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c  |  2 --
 drivers/gpu/drm/gma500/fbdev.c             |  3 ---
 drivers/gpu/drm/i915/display/intel_fbdev.c |  2 --
 drivers/gpu/drm/msm/msm_fbdev.c            |  2 --
 drivers/gpu/drm/omapdrm/omap_fbdev.c       |  2 --
 drivers/gpu/drm/radeon/radeon_fbdev.c      |  2 --
 drivers/gpu/drm/tegra/fbdev.c              |  2 --
 include/drm/drm_client.h                   | 10 ++++++++++
 16 files changed, 46 insertions(+), 35 deletions(-)

-- 
2.51.0

[PATCH 1/4] drm/client: Add client free callback to unprepare fb_helper

[Thomas Zimmermann]

Add free callback to struct drm_client_funcs. Invoke function to
free the client memory as part of the release process. Implement
free for fbdev emulation.

Fbdev emulation allocates and prepares client memory in
drm_fbdev_client_setup(). The release happens in fb_destroy from
struct fb_ops. Multiple implementations of this callback exist in
the various drivers that provide fbdev implementation. Each of them
needs to follow the implementation details of the fbdev setup code.

Adding a free callback for the client puts the unprepare and release
of the fbdev client in a single place.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/armada/armada_fbdev.c      |  2 --
 drivers/gpu/drm/clients/drm_fbdev_client.c | 17 +++++++++++++++--
 drivers/gpu/drm/drm_client.c               |  4 ++++
 drivers/gpu/drm/drm_fbdev_dma.c            |  4 ----
 drivers/gpu/drm/drm_fbdev_shmem.c          |  2 --
 drivers/gpu/drm/drm_fbdev_ttm.c            |  2 --
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c  |  2 --
 drivers/gpu/drm/gma500/fbdev.c             |  3 ---
 drivers/gpu/drm/i915/display/intel_fbdev.c |  2 --
 drivers/gpu/drm/msm/msm_fbdev.c            |  2 --
 drivers/gpu/drm/omapdrm/omap_fbdev.c       |  2 --
 drivers/gpu/drm/radeon/radeon_fbdev.c      |  2 --
 drivers/gpu/drm/tegra/fbdev.c              |  2 --
 include/drm/drm_client.h                   | 10 ++++++++++
 14 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/armada/armada_fbdev.c b/drivers/gpu/drm/armada/armada_fbdev.c
index cb53cc91bafb..22e2081bfa04 100644
--- a/drivers/gpu/drm/armada/armada_fbdev.c
+++ b/drivers/gpu/drm/armada/armada_fbdev.c
@@ -28,8 +28,6 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
 	fbh->fb->funcs->destroy(fbh->fb);
 
 	drm_client_release(&fbh->client);
-	drm_fb_helper_unprepare(fbh);
-	kfree(fbh);
 }
 
 static const struct fb_ops armada_fb_ops = {
diff --git a/drivers/gpu/drm/clients/drm_fbdev_client.c b/drivers/gpu/drm/clients/drm_fbdev_client.c
index f894ba52bdb5..5336accab1b6 100644
--- a/drivers/gpu/drm/clients/drm_fbdev_client.c
+++ b/drivers/gpu/drm/clients/drm_fbdev_client.c
@@ -13,16 +13,28 @@
  * struct drm_client_funcs
  */
 
+static void drm_fbdev_client_free(struct drm_client_dev *client)
+{
+	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+
+	drm_fb_helper_unprepare(fb_helper);
+	kfree(fb_helper);
+}
+
 static void drm_fbdev_client_unregister(struct drm_client_dev *client)
 {
 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
 
 	if (fb_helper->info) {
+		/*
+		 * Fully probed framebuffer device
+		 */
 		drm_fb_helper_unregister_info(fb_helper);
 	} else {
+		/*
+		 * Partially initialized client, no framebuffer device yet
+		 */
 		drm_client_release(&fb_helper->client);
-		drm_fb_helper_unprepare(fb_helper);
-		kfree(fb_helper);
 	}
 }
 
@@ -88,6 +100,7 @@ static int drm_fbdev_client_resume(struct drm_client_dev *client, bool holds_con
 
 static const struct drm_client_funcs drm_fbdev_client_funcs = {
 	.owner		= THIS_MODULE,
+	.free		= drm_fbdev_client_free,
 	.unregister	= drm_fbdev_client_unregister,
 	.restore	= drm_fbdev_client_restore,
 	.hotplug	= drm_fbdev_client_hotplug,
diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 3fa38d4ac70b..fe9c6d7083ea 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -168,6 +168,10 @@ void drm_client_release(struct drm_client_dev *client)
 
 	drm_client_modeset_free(client);
 	drm_client_close(client);
+
+	if (client->funcs && client->funcs->free)
+		client->funcs->free(client);
+
 	drm_dev_put(dev);
 }
 EXPORT_SYMBOL(drm_client_release);
diff --git a/drivers/gpu/drm/drm_fbdev_dma.c b/drivers/gpu/drm/drm_fbdev_dma.c
index 8bd626ef16c7..c6196293e424 100644
--- a/drivers/gpu/drm/drm_fbdev_dma.c
+++ b/drivers/gpu/drm/drm_fbdev_dma.c
@@ -57,8 +57,6 @@ static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
 	drm_client_buffer_vunmap(fb_helper->buffer);
 	drm_client_framebuffer_delete(fb_helper->buffer);
 	drm_client_release(&fb_helper->client);
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
 }
 
 static const struct fb_ops drm_fbdev_dma_fb_ops = {
@@ -92,8 +90,6 @@ static void drm_fbdev_dma_shadowed_fb_destroy(struct fb_info *info)
 	drm_client_buffer_vunmap(fb_helper->buffer);
 	drm_client_framebuffer_delete(fb_helper->buffer);
 	drm_client_release(&fb_helper->client);
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
 }
 
 static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
diff --git a/drivers/gpu/drm/drm_fbdev_shmem.c b/drivers/gpu/drm/drm_fbdev_shmem.c
index 1e827bf8b815..51573058df6f 100644
--- a/drivers/gpu/drm/drm_fbdev_shmem.c
+++ b/drivers/gpu/drm/drm_fbdev_shmem.c
@@ -65,8 +65,6 @@ static void drm_fbdev_shmem_fb_destroy(struct fb_info *info)
 	drm_client_buffer_vunmap(fb_helper->buffer);
 	drm_client_framebuffer_delete(fb_helper->buffer);
 	drm_client_release(&fb_helper->client);
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
 }
 
 static const struct fb_ops drm_fbdev_shmem_fb_ops = {
diff --git a/drivers/gpu/drm/drm_fbdev_ttm.c b/drivers/gpu/drm/drm_fbdev_ttm.c
index 85feb55bba11..ccf460fbc1f0 100644
--- a/drivers/gpu/drm/drm_fbdev_ttm.c
+++ b/drivers/gpu/drm/drm_fbdev_ttm.c
@@ -53,8 +53,6 @@ static void drm_fbdev_ttm_fb_destroy(struct fb_info *info)
 	drm_client_framebuffer_delete(fb_helper->buffer);
 
 	drm_client_release(&fb_helper->client);
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
 }
 
 static const struct fb_ops drm_fbdev_ttm_fb_ops = {
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index 93de25b77e68..a3bd21a827ad 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -42,8 +42,6 @@ static void exynos_drm_fb_destroy(struct fb_info *info)
 	drm_framebuffer_remove(fb);
 
 	drm_client_release(&fb_helper->client);
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
 }
 
 static const struct fb_ops exynos_drm_fb_ops = {
diff --git a/drivers/gpu/drm/gma500/fbdev.c b/drivers/gpu/drm/gma500/fbdev.c
index a6af21514cff..bc92fa24a1e2 100644
--- a/drivers/gpu/drm/gma500/fbdev.c
+++ b/drivers/gpu/drm/gma500/fbdev.c
@@ -84,9 +84,6 @@ static void psb_fbdev_fb_destroy(struct fb_info *info)
 	drm_gem_object_put(obj);
 
 	drm_client_release(&fb_helper->client);
-
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
 }
 
 static const struct fb_ops psb_fbdev_fb_ops = {
diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
index 3fbdf75415cc..d5f26c8bb102 100644
--- a/drivers/gpu/drm/i915/display/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
@@ -146,8 +146,6 @@ static void intel_fbdev_fb_destroy(struct fb_info *info)
 	drm_framebuffer_remove(fb_helper->fb);
 
 	drm_client_release(&fb_helper->client);
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
 }
 
 __diag_push();
diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
index b5969374d53f..aad6fb77f0de 100644
--- a/drivers/gpu/drm/msm/msm_fbdev.c
+++ b/drivers/gpu/drm/msm/msm_fbdev.c
@@ -52,8 +52,6 @@ static void msm_fbdev_fb_destroy(struct fb_info *info)
 	drm_framebuffer_remove(fb);
 
 	drm_client_release(&helper->client);
-	drm_fb_helper_unprepare(helper);
-	kfree(helper);
 }
 
 static const struct fb_ops msm_fb_ops = {
diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
index 948af7ec1130..b5df2923d2a6 100644
--- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
+++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
@@ -103,8 +103,6 @@ static void omap_fbdev_fb_destroy(struct fb_info *info)
 	drm_framebuffer_remove(fb);
 
 	drm_client_release(&helper->client);
-	drm_fb_helper_unprepare(helper);
-	kfree(helper);
 }
 
 /*
diff --git a/drivers/gpu/drm/radeon/radeon_fbdev.c b/drivers/gpu/drm/radeon/radeon_fbdev.c
index dc81b0c2dbff..4df6c9167bf0 100644
--- a/drivers/gpu/drm/radeon/radeon_fbdev.c
+++ b/drivers/gpu/drm/radeon/radeon_fbdev.c
@@ -184,8 +184,6 @@ static void radeon_fbdev_fb_destroy(struct fb_info *info)
 	radeon_fbdev_destroy_pinned_object(gobj);
 
 	drm_client_release(&fb_helper->client);
-	drm_fb_helper_unprepare(fb_helper);
-	kfree(fb_helper);
 }
 
 static const struct fb_ops radeon_fbdev_fb_ops = {
diff --git a/drivers/gpu/drm/tegra/fbdev.c b/drivers/gpu/drm/tegra/fbdev.c
index 1b70f5e164af..91aece6f34e0 100644
--- a/drivers/gpu/drm/tegra/fbdev.c
+++ b/drivers/gpu/drm/tegra/fbdev.c
@@ -53,8 +53,6 @@ static void tegra_fbdev_fb_destroy(struct fb_info *info)
 	drm_framebuffer_remove(fb);
 
 	drm_client_release(&helper->client);
-	drm_fb_helper_unprepare(helper);
-	kfree(helper);
 }
 
 static const struct fb_ops tegra_fb_ops = {
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index bdd845e383ef..eecb8d6e15c7 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -28,6 +28,16 @@ struct drm_client_funcs {
 	 */
 	struct module *owner;
 
+	/**
+	 * @free:
+	 *
+	 * Called when the client gets unregistered. Implementations should
+	 * release all client-specific data and free the memory.
+	 *
+	 * This callback is optional.
+	 */
+	void (*free)(struct drm_client_dev *client);
+
 	/**
 	 * @unregister:
 	 *
-- 
2.51.0

[PATCH 2/4] drm/log: Do not hold lock across drm_client_release()

[Thomas Zimmermann]

When calling drm_client_release(), the client is already quiescent.
Internal locks should therefore be dropped before the caller releases
the client.

In the case of the DRM log, concurrency originates from the console or
from client events. The console has been unregistered in the previous
line. The caller of the unregister callback, drm_log_client_unregister(),
holds clientlist_mutex from struct drm_device to protect against concurrent
client events. It is therefore safe to release the client without holding
locks.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/clients/drm_log.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/clients/drm_log.c b/drivers/gpu/drm/clients/drm_log.c
index d239f1e3c456..116e0ef9ae5d 100644
--- a/drivers/gpu/drm/clients/drm_log.c
+++ b/drivers/gpu/drm/clients/drm_log.c
@@ -302,8 +302,8 @@ static void drm_log_client_unregister(struct drm_client_dev *client)
 
 	mutex_lock(&dlog->lock);
 	drm_log_free_scanout(client);
-	drm_client_release(client);
 	mutex_unlock(&dlog->lock);
+	drm_client_release(client);
 	kfree(dlog);
 	drm_dbg(dev, "Unregistered with drm log\n");
 }
-- 
2.51.0

[PATCH 3/4] drm/log: Add free callback

[Thomas Zimmermann]

Free the client memory in the client free callback. Also move the
debugging output into the free callback: drm_client_release() puts
the reference on the DRM device, so pointers to the device should
be considered dangling afterwards.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/clients/drm_log.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/clients/drm_log.c b/drivers/gpu/drm/clients/drm_log.c
index 116e0ef9ae5d..470df4148e96 100644
--- a/drivers/gpu/drm/clients/drm_log.c
+++ b/drivers/gpu/drm/clients/drm_log.c
@@ -293,19 +293,26 @@ static void drm_log_free_scanout(struct drm_client_dev *client)
 	}
 }
 
-static void drm_log_client_unregister(struct drm_client_dev *client)
+static void drm_log_client_free(struct drm_client_dev *client)
 {
 	struct drm_log *dlog = client_to_drm_log(client);
 	struct drm_device *dev = client->dev;
 
+	kfree(dlog);
+
+	drm_dbg(dev, "Unregistered with drm log\n");
+}
+
+static void drm_log_client_unregister(struct drm_client_dev *client)
+{
+	struct drm_log *dlog = client_to_drm_log(client);
+
 	unregister_console(&dlog->con);
 
 	mutex_lock(&dlog->lock);
 	drm_log_free_scanout(client);
 	mutex_unlock(&dlog->lock);
 	drm_client_release(client);
-	kfree(dlog);
-	drm_dbg(dev, "Unregistered with drm log\n");
 }
 
 static int drm_log_client_hotplug(struct drm_client_dev *client)
@@ -339,6 +346,7 @@ static int drm_log_client_resume(struct drm_client_dev *client, bool _console_lo
 
 static const struct drm_client_funcs drm_log_client_funcs = {
 	.owner		= THIS_MODULE,
+	.free		= drm_log_client_free,
 	.unregister	= drm_log_client_unregister,
 	.hotplug	= drm_log_client_hotplug,
 	.suspend	= drm_log_client_suspend,
-- 
2.51.0

[PATCH 4/4] drm/client: Do not free client memory by default

[Thomas Zimmermann]

Make no assumption on the allocation of the client's memory. For
example, amdgpu stores a client within another data structures,
where it cannot be freed by itself.

The correct place to free the client's memory is the client's free
callback. All existing clients implement this.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/drm_client_event.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_client_event.c b/drivers/gpu/drm/drm_client_event.c
index c83196ad8b59..f36fe0392ce6 100644
--- a/drivers/gpu/drm/drm_client_event.c
+++ b/drivers/gpu/drm/drm_client_event.c
@@ -39,12 +39,13 @@ void drm_client_dev_unregister(struct drm_device *dev)
 	mutex_lock(&dev->clientlist_mutex);
 	list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
 		list_del(&client->list);
-		if (client->funcs && client->funcs->unregister) {
+		/*
+		 * Unregistering consumes and frees the client.
+		 */
+		if (client->funcs && client->funcs->unregister)
 			client->funcs->unregister(client);
-		} else {
+		else
 			drm_client_release(client);
-			kfree(client);
-		}
 	}
 	mutex_unlock(&dev->clientlist_mutex);
 }
-- 
2.51.0

Re: [PATCH 1/4] drm/client: Add client free callback to unprepare fb_helper

[Dmitry Baryshkov]

On Thu, Oct 09, 2025 at 03:16:28PM +0200, Thomas Zimmermann wrote:
> Add free callback to struct drm_client_funcs. Invoke function to
> free the client memory as part of the release process. Implement
> free for fbdev emulation.
> 
> Fbdev emulation allocates and prepares client memory in
> drm_fbdev_client_setup(). The release happens in fb_destroy from
> struct fb_ops. Multiple implementations of this callback exist in
> the various drivers that provide fbdev implementation. Each of them
> needs to follow the implementation details of the fbdev setup code.
> 
> Adding a free callback for the client puts the unprepare and release
> of the fbdev client in a single place.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/armada/armada_fbdev.c      |  2 --
>  drivers/gpu/drm/clients/drm_fbdev_client.c | 17 +++++++++++++++--
>  drivers/gpu/drm/drm_client.c               |  4 ++++
>  drivers/gpu/drm/drm_fbdev_dma.c            |  4 ----
>  drivers/gpu/drm/drm_fbdev_shmem.c          |  2 --
>  drivers/gpu/drm/drm_fbdev_ttm.c            |  2 --
>  drivers/gpu/drm/exynos/exynos_drm_fbdev.c  |  2 --
>  drivers/gpu/drm/gma500/fbdev.c             |  3 ---
>  drivers/gpu/drm/i915/display/intel_fbdev.c |  2 --
>  drivers/gpu/drm/msm/msm_fbdev.c            |  2 --

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> # core, msm

>  drivers/gpu/drm/omapdrm/omap_fbdev.c       |  2 --
>  drivers/gpu/drm/radeon/radeon_fbdev.c      |  2 --
>  drivers/gpu/drm/tegra/fbdev.c              |  2 --
>  include/drm/drm_client.h                   | 10 ++++++++++
>  14 files changed, 29 insertions(+), 27 deletions(-)
> 

-- 
With best wishes
Dmitry

Re: [PATCH 2/4] drm/log: Do not hold lock across drm_client_release()

[Jocelyn Falempe]

On 09/10/2025 15:16, Thomas Zimmermann wrote:
> When calling drm_client_release(), the client is already quiescent.
> Internal locks should therefore be dropped before the caller releases
> the client.
> 
> In the case of the DRM log, concurrency originates from the console or
> from client events. The console has been unregistered in the previous
> line. The caller of the unregister callback, drm_log_client_unregister(),
> holds clientlist_mutex from struct drm_device to protect against concurrent
> client events. It is therefore safe to release the client without holding
> locks.

Thanks, I agree, it should be safe to move drm_client_release() after 
the lock.

Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/clients/drm_log.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/clients/drm_log.c b/drivers/gpu/drm/clients/drm_log.c
> index d239f1e3c456..116e0ef9ae5d 100644
> --- a/drivers/gpu/drm/clients/drm_log.c
> +++ b/drivers/gpu/drm/clients/drm_log.c
> @@ -302,8 +302,8 @@ static void drm_log_client_unregister(struct drm_client_dev *client)
>   
>   	mutex_lock(&dlog->lock);
>   	drm_log_free_scanout(client);
> -	drm_client_release(client);
>   	mutex_unlock(&dlog->lock);
> +	drm_client_release(client);
>   	kfree(dlog);
>   	drm_dbg(dev, "Unregistered with drm log\n");
>   }

Re: [PATCH 3/4] drm/log: Add free callback

[Jocelyn Falempe]

On 09/10/2025 15:16, Thomas Zimmermann wrote:
> Free the client memory in the client free callback. Also move the
> debugging output into the free callback: drm_client_release() puts
> the reference on the DRM device, so pointers to the device should
> be considered dangling afterwards.

Thanks, it looks good to me.

Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/clients/drm_log.c | 14 +++++++++++---
>   1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/clients/drm_log.c b/drivers/gpu/drm/clients/drm_log.c
> index 116e0ef9ae5d..470df4148e96 100644
> --- a/drivers/gpu/drm/clients/drm_log.c
> +++ b/drivers/gpu/drm/clients/drm_log.c
> @@ -293,19 +293,26 @@ static void drm_log_free_scanout(struct drm_client_dev *client)
>   	}
>   }
>   
> -static void drm_log_client_unregister(struct drm_client_dev *client)
> +static void drm_log_client_free(struct drm_client_dev *client)
>   {
>   	struct drm_log *dlog = client_to_drm_log(client);
>   	struct drm_device *dev = client->dev;
>   
> +	kfree(dlog);
> +
> +	drm_dbg(dev, "Unregistered with drm log\n");
> +}
> +
> +static void drm_log_client_unregister(struct drm_client_dev *client)
> +{
> +	struct drm_log *dlog = client_to_drm_log(client);
> +
>   	unregister_console(&dlog->con);
>   
>   	mutex_lock(&dlog->lock);
>   	drm_log_free_scanout(client);
>   	mutex_unlock(&dlog->lock);
>   	drm_client_release(client);
> -	kfree(dlog);
> -	drm_dbg(dev, "Unregistered with drm log\n");
>   }
>   
>   static int drm_log_client_hotplug(struct drm_client_dev *client)
> @@ -339,6 +346,7 @@ static int drm_log_client_resume(struct drm_client_dev *client, bool _console_lo
>   
>   static const struct drm_client_funcs drm_log_client_funcs = {
>   	.owner		= THIS_MODULE,
> +	.free		= drm_log_client_free,
>   	.unregister	= drm_log_client_unregister,
>   	.hotplug	= drm_log_client_hotplug,
>   	.suspend	= drm_log_client_suspend,

Re: [PATCH 4/4] drm/client: Do not free client memory by default

[Jocelyn Falempe]

On 09/10/2025 15:16, Thomas Zimmermann wrote:
> Make no assumption on the allocation of the client's memory. For
> example, amdgpu stores a client within another data structures,
> where it cannot be freed by itself.
> 
> The correct place to free the client's memory is the client's free
> callback. All existing clients implement this.

Thanks, it looks good to me.

Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>


> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/drm_client_event.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_client_event.c b/drivers/gpu/drm/drm_client_event.c
> index c83196ad8b59..f36fe0392ce6 100644
> --- a/drivers/gpu/drm/drm_client_event.c
> +++ b/drivers/gpu/drm/drm_client_event.c
> @@ -39,12 +39,13 @@ void drm_client_dev_unregister(struct drm_device *dev)
>   	mutex_lock(&dev->clientlist_mutex);
>   	list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
>   		list_del(&client->list);
> -		if (client->funcs && client->funcs->unregister) {
> +		/*
> +		 * Unregistering consumes and frees the client.
> +		 */
> +		if (client->funcs && client->funcs->unregister)
>   			client->funcs->unregister(client);
> -		} else {
> +		else
>   			drm_client_release(client);
> -			kfree(client);
> -		}
>   	}
>   	mutex_unlock(&dev->clientlist_mutex);
>   }

Re: [PATCH 1/4] drm/client: Add client free callback to unprepare fb_helper

[Tomi Valkeinen]

On 09/10/2025 16:16, Thomas Zimmermann wrote:
> Add free callback to struct drm_client_funcs. Invoke function to
> free the client memory as part of the release process. Implement
> free for fbdev emulation.
> 
> Fbdev emulation allocates and prepares client memory in
> drm_fbdev_client_setup(). The release happens in fb_destroy from
> struct fb_ops. Multiple implementations of this callback exist in
> the various drivers that provide fbdev implementation. Each of them
> needs to follow the implementation details of the fbdev setup code.
> 
> Adding a free callback for the client puts the unprepare and release
> of the fbdev client in a single place.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/armada/armada_fbdev.c      |  2 --
>  drivers/gpu/drm/clients/drm_fbdev_client.c | 17 +++++++++++++++--
>  drivers/gpu/drm/drm_client.c               |  4 ++++
>  drivers/gpu/drm/drm_fbdev_dma.c            |  4 ----
>  drivers/gpu/drm/drm_fbdev_shmem.c          |  2 --
>  drivers/gpu/drm/drm_fbdev_ttm.c            |  2 --
>  drivers/gpu/drm/exynos/exynos_drm_fbdev.c  |  2 --
>  drivers/gpu/drm/gma500/fbdev.c             |  3 ---
>  drivers/gpu/drm/i915/display/intel_fbdev.c |  2 --
>  drivers/gpu/drm/msm/msm_fbdev.c            |  2 --
>  drivers/gpu/drm/omapdrm/omap_fbdev.c       |  2 --

For omapdrm:

Acked-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

 Tomi

>  drivers/gpu/drm/radeon/radeon_fbdev.c      |  2 --
>  drivers/gpu/drm/tegra/fbdev.c              |  2 --
>  include/drm/drm_client.h                   | 10 ++++++++++
>  14 files changed, 29 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/armada/armada_fbdev.c b/drivers/gpu/drm/armada/armada_fbdev.c
> index cb53cc91bafb..22e2081bfa04 100644
> --- a/drivers/gpu/drm/armada/armada_fbdev.c
> +++ b/drivers/gpu/drm/armada/armada_fbdev.c
> @@ -28,8 +28,6 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
>  	fbh->fb->funcs->destroy(fbh->fb);
>  
>  	drm_client_release(&fbh->client);
> -	drm_fb_helper_unprepare(fbh);
> -	kfree(fbh);
>  }
>  
>  static const struct fb_ops armada_fb_ops = {
> diff --git a/drivers/gpu/drm/clients/drm_fbdev_client.c b/drivers/gpu/drm/clients/drm_fbdev_client.c
> index f894ba52bdb5..5336accab1b6 100644
> --- a/drivers/gpu/drm/clients/drm_fbdev_client.c
> +++ b/drivers/gpu/drm/clients/drm_fbdev_client.c
> @@ -13,16 +13,28 @@
>   * struct drm_client_funcs
>   */
>  
> +static void drm_fbdev_client_free(struct drm_client_dev *client)
> +{
> +	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
> +
> +	drm_fb_helper_unprepare(fb_helper);
> +	kfree(fb_helper);
> +}
> +
>  static void drm_fbdev_client_unregister(struct drm_client_dev *client)
>  {
>  	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
>  
>  	if (fb_helper->info) {
> +		/*
> +		 * Fully probed framebuffer device
> +		 */
>  		drm_fb_helper_unregister_info(fb_helper);
>  	} else {
> +		/*
> +		 * Partially initialized client, no framebuffer device yet
> +		 */
>  		drm_client_release(&fb_helper->client);
> -		drm_fb_helper_unprepare(fb_helper);
> -		kfree(fb_helper);
>  	}
>  }
>  
> @@ -88,6 +100,7 @@ static int drm_fbdev_client_resume(struct drm_client_dev *client, bool holds_con
>  
>  static const struct drm_client_funcs drm_fbdev_client_funcs = {
>  	.owner		= THIS_MODULE,
> +	.free		= drm_fbdev_client_free,
>  	.unregister	= drm_fbdev_client_unregister,
>  	.restore	= drm_fbdev_client_restore,
>  	.hotplug	= drm_fbdev_client_hotplug,
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 3fa38d4ac70b..fe9c6d7083ea 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -168,6 +168,10 @@ void drm_client_release(struct drm_client_dev *client)
>  
>  	drm_client_modeset_free(client);
>  	drm_client_close(client);
> +
> +	if (client->funcs && client->funcs->free)
> +		client->funcs->free(client);
> +
>  	drm_dev_put(dev);
>  }
>  EXPORT_SYMBOL(drm_client_release);
> diff --git a/drivers/gpu/drm/drm_fbdev_dma.c b/drivers/gpu/drm/drm_fbdev_dma.c
> index 8bd626ef16c7..c6196293e424 100644
> --- a/drivers/gpu/drm/drm_fbdev_dma.c
> +++ b/drivers/gpu/drm/drm_fbdev_dma.c
> @@ -57,8 +57,6 @@ static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
>  	drm_client_buffer_vunmap(fb_helper->buffer);
>  	drm_client_framebuffer_delete(fb_helper->buffer);
>  	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>  }
>  
>  static const struct fb_ops drm_fbdev_dma_fb_ops = {
> @@ -92,8 +90,6 @@ static void drm_fbdev_dma_shadowed_fb_destroy(struct fb_info *info)
>  	drm_client_buffer_vunmap(fb_helper->buffer);
>  	drm_client_framebuffer_delete(fb_helper->buffer);
>  	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>  }
>  
>  static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
> diff --git a/drivers/gpu/drm/drm_fbdev_shmem.c b/drivers/gpu/drm/drm_fbdev_shmem.c
> index 1e827bf8b815..51573058df6f 100644
> --- a/drivers/gpu/drm/drm_fbdev_shmem.c
> +++ b/drivers/gpu/drm/drm_fbdev_shmem.c
> @@ -65,8 +65,6 @@ static void drm_fbdev_shmem_fb_destroy(struct fb_info *info)
>  	drm_client_buffer_vunmap(fb_helper->buffer);
>  	drm_client_framebuffer_delete(fb_helper->buffer);
>  	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>  }
>  
>  static const struct fb_ops drm_fbdev_shmem_fb_ops = {
> diff --git a/drivers/gpu/drm/drm_fbdev_ttm.c b/drivers/gpu/drm/drm_fbdev_ttm.c
> index 85feb55bba11..ccf460fbc1f0 100644
> --- a/drivers/gpu/drm/drm_fbdev_ttm.c
> +++ b/drivers/gpu/drm/drm_fbdev_ttm.c
> @@ -53,8 +53,6 @@ static void drm_fbdev_ttm_fb_destroy(struct fb_info *info)
>  	drm_client_framebuffer_delete(fb_helper->buffer);
>  
>  	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>  }
>  
>  static const struct fb_ops drm_fbdev_ttm_fb_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> index 93de25b77e68..a3bd21a827ad 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> @@ -42,8 +42,6 @@ static void exynos_drm_fb_destroy(struct fb_info *info)
>  	drm_framebuffer_remove(fb);
>  
>  	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>  }
>  
>  static const struct fb_ops exynos_drm_fb_ops = {
> diff --git a/drivers/gpu/drm/gma500/fbdev.c b/drivers/gpu/drm/gma500/fbdev.c
> index a6af21514cff..bc92fa24a1e2 100644
> --- a/drivers/gpu/drm/gma500/fbdev.c
> +++ b/drivers/gpu/drm/gma500/fbdev.c
> @@ -84,9 +84,6 @@ static void psb_fbdev_fb_destroy(struct fb_info *info)
>  	drm_gem_object_put(obj);
>  
>  	drm_client_release(&fb_helper->client);
> -
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>  }
>  
>  static const struct fb_ops psb_fbdev_fb_ops = {
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 3fbdf75415cc..d5f26c8bb102 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -146,8 +146,6 @@ static void intel_fbdev_fb_destroy(struct fb_info *info)
>  	drm_framebuffer_remove(fb_helper->fb);
>  
>  	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>  }
>  
>  __diag_push();
> diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
> index b5969374d53f..aad6fb77f0de 100644
> --- a/drivers/gpu/drm/msm/msm_fbdev.c
> +++ b/drivers/gpu/drm/msm/msm_fbdev.c
> @@ -52,8 +52,6 @@ static void msm_fbdev_fb_destroy(struct fb_info *info)
>  	drm_framebuffer_remove(fb);
>  
>  	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>  }
>  
>  static const struct fb_ops msm_fb_ops = {
> diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> index 948af7ec1130..b5df2923d2a6 100644
> --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
> +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> @@ -103,8 +103,6 @@ static void omap_fbdev_fb_destroy(struct fb_info *info)
>  	drm_framebuffer_remove(fb);
>  
>  	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>  }
>  
>  /*
> diff --git a/drivers/gpu/drm/radeon/radeon_fbdev.c b/drivers/gpu/drm/radeon/radeon_fbdev.c
> index dc81b0c2dbff..4df6c9167bf0 100644
> --- a/drivers/gpu/drm/radeon/radeon_fbdev.c
> +++ b/drivers/gpu/drm/radeon/radeon_fbdev.c
> @@ -184,8 +184,6 @@ static void radeon_fbdev_fb_destroy(struct fb_info *info)
>  	radeon_fbdev_destroy_pinned_object(gobj);
>  
>  	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>  }
>  
>  static const struct fb_ops radeon_fbdev_fb_ops = {
> diff --git a/drivers/gpu/drm/tegra/fbdev.c b/drivers/gpu/drm/tegra/fbdev.c
> index 1b70f5e164af..91aece6f34e0 100644
> --- a/drivers/gpu/drm/tegra/fbdev.c
> +++ b/drivers/gpu/drm/tegra/fbdev.c
> @@ -53,8 +53,6 @@ static void tegra_fbdev_fb_destroy(struct fb_info *info)
>  	drm_framebuffer_remove(fb);
>  
>  	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>  }
>  
>  static const struct fb_ops tegra_fb_ops = {
> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
> index bdd845e383ef..eecb8d6e15c7 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -28,6 +28,16 @@ struct drm_client_funcs {
>  	 */
>  	struct module *owner;
>  
> +	/**
> +	 * @free:
> +	 *
> +	 * Called when the client gets unregistered. Implementations should
> +	 * release all client-specific data and free the memory.
> +	 *
> +	 * This callback is optional.
> +	 */
> +	void (*free)(struct drm_client_dev *client);
> +
>  	/**
>  	 * @unregister:
>  	 *

Re: [PATCH 1/4] drm/client: Add client free callback to unprepare fb_helper

[Patrik Jakobsson]

On Thu, Oct 9, 2025 at 3:31 PM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>
> Add free callback to struct drm_client_funcs. Invoke function to
> free the client memory as part of the release process. Implement
> free for fbdev emulation.
>
> Fbdev emulation allocates and prepares client memory in
> drm_fbdev_client_setup(). The release happens in fb_destroy from
> struct fb_ops. Multiple implementations of this callback exist in
> the various drivers that provide fbdev implementation. Each of them
> needs to follow the implementation details of the fbdev setup code.
>
> Adding a free callback for the client puts the unprepare and release
> of the fbdev client in a single place.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

For gma500:
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>

> ---
>  drivers/gpu/drm/armada/armada_fbdev.c      |  2 --
>  drivers/gpu/drm/clients/drm_fbdev_client.c | 17 +++++++++++++++--
>  drivers/gpu/drm/drm_client.c               |  4 ++++
>  drivers/gpu/drm/drm_fbdev_dma.c            |  4 ----
>  drivers/gpu/drm/drm_fbdev_shmem.c          |  2 --
>  drivers/gpu/drm/drm_fbdev_ttm.c            |  2 --
>  drivers/gpu/drm/exynos/exynos_drm_fbdev.c  |  2 --
>  drivers/gpu/drm/gma500/fbdev.c             |  3 ---
>  drivers/gpu/drm/i915/display/intel_fbdev.c |  2 --
>  drivers/gpu/drm/msm/msm_fbdev.c            |  2 --
>  drivers/gpu/drm/omapdrm/omap_fbdev.c       |  2 --
>  drivers/gpu/drm/radeon/radeon_fbdev.c      |  2 --
>  drivers/gpu/drm/tegra/fbdev.c              |  2 --
>  include/drm/drm_client.h                   | 10 ++++++++++
>  14 files changed, 29 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/armada/armada_fbdev.c b/drivers/gpu/drm/armada/armada_fbdev.c
> index cb53cc91bafb..22e2081bfa04 100644
> --- a/drivers/gpu/drm/armada/armada_fbdev.c
> +++ b/drivers/gpu/drm/armada/armada_fbdev.c
> @@ -28,8 +28,6 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
>         fbh->fb->funcs->destroy(fbh->fb);
>
>         drm_client_release(&fbh->client);
> -       drm_fb_helper_unprepare(fbh);
> -       kfree(fbh);
>  }
>
>  static const struct fb_ops armada_fb_ops = {
> diff --git a/drivers/gpu/drm/clients/drm_fbdev_client.c b/drivers/gpu/drm/clients/drm_fbdev_client.c
> index f894ba52bdb5..5336accab1b6 100644
> --- a/drivers/gpu/drm/clients/drm_fbdev_client.c
> +++ b/drivers/gpu/drm/clients/drm_fbdev_client.c
> @@ -13,16 +13,28 @@
>   * struct drm_client_funcs
>   */
>
> +static void drm_fbdev_client_free(struct drm_client_dev *client)
> +{
> +       struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
> +
> +       drm_fb_helper_unprepare(fb_helper);
> +       kfree(fb_helper);
> +}
> +
>  static void drm_fbdev_client_unregister(struct drm_client_dev *client)
>  {
>         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
>
>         if (fb_helper->info) {
> +               /*
> +                * Fully probed framebuffer device
> +                */
>                 drm_fb_helper_unregister_info(fb_helper);
>         } else {
> +               /*
> +                * Partially initialized client, no framebuffer device yet
> +                */
>                 drm_client_release(&fb_helper->client);
> -               drm_fb_helper_unprepare(fb_helper);
> -               kfree(fb_helper);
>         }
>  }
>
> @@ -88,6 +100,7 @@ static int drm_fbdev_client_resume(struct drm_client_dev *client, bool holds_con
>
>  static const struct drm_client_funcs drm_fbdev_client_funcs = {
>         .owner          = THIS_MODULE,
> +       .free           = drm_fbdev_client_free,
>         .unregister     = drm_fbdev_client_unregister,
>         .restore        = drm_fbdev_client_restore,
>         .hotplug        = drm_fbdev_client_hotplug,
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 3fa38d4ac70b..fe9c6d7083ea 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -168,6 +168,10 @@ void drm_client_release(struct drm_client_dev *client)
>
>         drm_client_modeset_free(client);
>         drm_client_close(client);
> +
> +       if (client->funcs && client->funcs->free)
> +               client->funcs->free(client);
> +
>         drm_dev_put(dev);
>  }
>  EXPORT_SYMBOL(drm_client_release);
> diff --git a/drivers/gpu/drm/drm_fbdev_dma.c b/drivers/gpu/drm/drm_fbdev_dma.c
> index 8bd626ef16c7..c6196293e424 100644
> --- a/drivers/gpu/drm/drm_fbdev_dma.c
> +++ b/drivers/gpu/drm/drm_fbdev_dma.c
> @@ -57,8 +57,6 @@ static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
>         drm_client_buffer_vunmap(fb_helper->buffer);
>         drm_client_framebuffer_delete(fb_helper->buffer);
>         drm_client_release(&fb_helper->client);
> -       drm_fb_helper_unprepare(fb_helper);
> -       kfree(fb_helper);
>  }
>
>  static const struct fb_ops drm_fbdev_dma_fb_ops = {
> @@ -92,8 +90,6 @@ static void drm_fbdev_dma_shadowed_fb_destroy(struct fb_info *info)
>         drm_client_buffer_vunmap(fb_helper->buffer);
>         drm_client_framebuffer_delete(fb_helper->buffer);
>         drm_client_release(&fb_helper->client);
> -       drm_fb_helper_unprepare(fb_helper);
> -       kfree(fb_helper);
>  }
>
>  static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
> diff --git a/drivers/gpu/drm/drm_fbdev_shmem.c b/drivers/gpu/drm/drm_fbdev_shmem.c
> index 1e827bf8b815..51573058df6f 100644
> --- a/drivers/gpu/drm/drm_fbdev_shmem.c
> +++ b/drivers/gpu/drm/drm_fbdev_shmem.c
> @@ -65,8 +65,6 @@ static void drm_fbdev_shmem_fb_destroy(struct fb_info *info)
>         drm_client_buffer_vunmap(fb_helper->buffer);
>         drm_client_framebuffer_delete(fb_helper->buffer);
>         drm_client_release(&fb_helper->client);
> -       drm_fb_helper_unprepare(fb_helper);
> -       kfree(fb_helper);
>  }
>
>  static const struct fb_ops drm_fbdev_shmem_fb_ops = {
> diff --git a/drivers/gpu/drm/drm_fbdev_ttm.c b/drivers/gpu/drm/drm_fbdev_ttm.c
> index 85feb55bba11..ccf460fbc1f0 100644
> --- a/drivers/gpu/drm/drm_fbdev_ttm.c
> +++ b/drivers/gpu/drm/drm_fbdev_ttm.c
> @@ -53,8 +53,6 @@ static void drm_fbdev_ttm_fb_destroy(struct fb_info *info)
>         drm_client_framebuffer_delete(fb_helper->buffer);
>
>         drm_client_release(&fb_helper->client);
> -       drm_fb_helper_unprepare(fb_helper);
> -       kfree(fb_helper);
>  }
>
>  static const struct fb_ops drm_fbdev_ttm_fb_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> index 93de25b77e68..a3bd21a827ad 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> @@ -42,8 +42,6 @@ static void exynos_drm_fb_destroy(struct fb_info *info)
>         drm_framebuffer_remove(fb);
>
>         drm_client_release(&fb_helper->client);
> -       drm_fb_helper_unprepare(fb_helper);
> -       kfree(fb_helper);
>  }
>
>  static const struct fb_ops exynos_drm_fb_ops = {
> diff --git a/drivers/gpu/drm/gma500/fbdev.c b/drivers/gpu/drm/gma500/fbdev.c
> index a6af21514cff..bc92fa24a1e2 100644
> --- a/drivers/gpu/drm/gma500/fbdev.c
> +++ b/drivers/gpu/drm/gma500/fbdev.c
> @@ -84,9 +84,6 @@ static void psb_fbdev_fb_destroy(struct fb_info *info)
>         drm_gem_object_put(obj);
>
>         drm_client_release(&fb_helper->client);
> -
> -       drm_fb_helper_unprepare(fb_helper);
> -       kfree(fb_helper);
>  }
>
>  static const struct fb_ops psb_fbdev_fb_ops = {
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 3fbdf75415cc..d5f26c8bb102 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -146,8 +146,6 @@ static void intel_fbdev_fb_destroy(struct fb_info *info)
>         drm_framebuffer_remove(fb_helper->fb);
>
>         drm_client_release(&fb_helper->client);
> -       drm_fb_helper_unprepare(fb_helper);
> -       kfree(fb_helper);
>  }
>
>  __diag_push();
> diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
> index b5969374d53f..aad6fb77f0de 100644
> --- a/drivers/gpu/drm/msm/msm_fbdev.c
> +++ b/drivers/gpu/drm/msm/msm_fbdev.c
> @@ -52,8 +52,6 @@ static void msm_fbdev_fb_destroy(struct fb_info *info)
>         drm_framebuffer_remove(fb);
>
>         drm_client_release(&helper->client);
> -       drm_fb_helper_unprepare(helper);
> -       kfree(helper);
>  }
>
>  static const struct fb_ops msm_fb_ops = {
> diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> index 948af7ec1130..b5df2923d2a6 100644
> --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
> +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> @@ -103,8 +103,6 @@ static void omap_fbdev_fb_destroy(struct fb_info *info)
>         drm_framebuffer_remove(fb);
>
>         drm_client_release(&helper->client);
> -       drm_fb_helper_unprepare(helper);
> -       kfree(helper);
>  }
>
>  /*
> diff --git a/drivers/gpu/drm/radeon/radeon_fbdev.c b/drivers/gpu/drm/radeon/radeon_fbdev.c
> index dc81b0c2dbff..4df6c9167bf0 100644
> --- a/drivers/gpu/drm/radeon/radeon_fbdev.c
> +++ b/drivers/gpu/drm/radeon/radeon_fbdev.c
> @@ -184,8 +184,6 @@ static void radeon_fbdev_fb_destroy(struct fb_info *info)
>         radeon_fbdev_destroy_pinned_object(gobj);
>
>         drm_client_release(&fb_helper->client);
> -       drm_fb_helper_unprepare(fb_helper);
> -       kfree(fb_helper);
>  }
>
>  static const struct fb_ops radeon_fbdev_fb_ops = {
> diff --git a/drivers/gpu/drm/tegra/fbdev.c b/drivers/gpu/drm/tegra/fbdev.c
> index 1b70f5e164af..91aece6f34e0 100644
> --- a/drivers/gpu/drm/tegra/fbdev.c
> +++ b/drivers/gpu/drm/tegra/fbdev.c
> @@ -53,8 +53,6 @@ static void tegra_fbdev_fb_destroy(struct fb_info *info)
>         drm_framebuffer_remove(fb);
>
>         drm_client_release(&helper->client);
> -       drm_fb_helper_unprepare(helper);
> -       kfree(helper);
>  }
>
>  static const struct fb_ops tegra_fb_ops = {
> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
> index bdd845e383ef..eecb8d6e15c7 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -28,6 +28,16 @@ struct drm_client_funcs {
>          */
>         struct module *owner;
>
> +       /**
> +        * @free:
> +        *
> +        * Called when the client gets unregistered. Implementations should
> +        * release all client-specific data and free the memory.
> +        *
> +        * This callback is optional.
> +        */
> +       void (*free)(struct drm_client_dev *client);
> +
>         /**
>          * @unregister:
>          *
> --
> 2.51.0
>

Re: [PATCH 1/4] drm/client: Add client free callback to unprepare fb_helper

[Thomas Zimmermann]

Acked by Jani via irc to go through  drm-misc

Am 09.10.25 um 15:16 schrieb Thomas Zimmermann:
> Add free callback to struct drm_client_funcs. Invoke function to
> free the client memory as part of the release process. Implement
> free for fbdev emulation.
>
> Fbdev emulation allocates and prepares client memory in
> drm_fbdev_client_setup(). The release happens in fb_destroy from
> struct fb_ops. Multiple implementations of this callback exist in
> the various drivers that provide fbdev implementation. Each of them
> needs to follow the implementation details of the fbdev setup code.
>
> Adding a free callback for the client puts the unprepare and release
> of the fbdev client in a single place.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/armada/armada_fbdev.c      |  2 --
>   drivers/gpu/drm/clients/drm_fbdev_client.c | 17 +++++++++++++++--
>   drivers/gpu/drm/drm_client.c               |  4 ++++
>   drivers/gpu/drm/drm_fbdev_dma.c            |  4 ----
>   drivers/gpu/drm/drm_fbdev_shmem.c          |  2 --
>   drivers/gpu/drm/drm_fbdev_ttm.c            |  2 --
>   drivers/gpu/drm/exynos/exynos_drm_fbdev.c  |  2 --
>   drivers/gpu/drm/gma500/fbdev.c             |  3 ---
>   drivers/gpu/drm/i915/display/intel_fbdev.c |  2 --
>   drivers/gpu/drm/msm/msm_fbdev.c            |  2 --
>   drivers/gpu/drm/omapdrm/omap_fbdev.c       |  2 --
>   drivers/gpu/drm/radeon/radeon_fbdev.c      |  2 --
>   drivers/gpu/drm/tegra/fbdev.c              |  2 --
>   include/drm/drm_client.h                   | 10 ++++++++++
>   14 files changed, 29 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/armada/armada_fbdev.c b/drivers/gpu/drm/armada/armada_fbdev.c
> index cb53cc91bafb..22e2081bfa04 100644
> --- a/drivers/gpu/drm/armada/armada_fbdev.c
> +++ b/drivers/gpu/drm/armada/armada_fbdev.c
> @@ -28,8 +28,6 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
>   	fbh->fb->funcs->destroy(fbh->fb);
>   
>   	drm_client_release(&fbh->client);
> -	drm_fb_helper_unprepare(fbh);
> -	kfree(fbh);
>   }
>   
>   static const struct fb_ops armada_fb_ops = {
> diff --git a/drivers/gpu/drm/clients/drm_fbdev_client.c b/drivers/gpu/drm/clients/drm_fbdev_client.c
> index f894ba52bdb5..5336accab1b6 100644
> --- a/drivers/gpu/drm/clients/drm_fbdev_client.c
> +++ b/drivers/gpu/drm/clients/drm_fbdev_client.c
> @@ -13,16 +13,28 @@
>    * struct drm_client_funcs
>    */
>   
> +static void drm_fbdev_client_free(struct drm_client_dev *client)
> +{
> +	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
> +
> +	drm_fb_helper_unprepare(fb_helper);
> +	kfree(fb_helper);
> +}
> +
>   static void drm_fbdev_client_unregister(struct drm_client_dev *client)
>   {
>   	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
>   
>   	if (fb_helper->info) {
> +		/*
> +		 * Fully probed framebuffer device
> +		 */
>   		drm_fb_helper_unregister_info(fb_helper);
>   	} else {
> +		/*
> +		 * Partially initialized client, no framebuffer device yet
> +		 */
>   		drm_client_release(&fb_helper->client);
> -		drm_fb_helper_unprepare(fb_helper);
> -		kfree(fb_helper);
>   	}
>   }
>   
> @@ -88,6 +100,7 @@ static int drm_fbdev_client_resume(struct drm_client_dev *client, bool holds_con
>   
>   static const struct drm_client_funcs drm_fbdev_client_funcs = {
>   	.owner		= THIS_MODULE,
> +	.free		= drm_fbdev_client_free,
>   	.unregister	= drm_fbdev_client_unregister,
>   	.restore	= drm_fbdev_client_restore,
>   	.hotplug	= drm_fbdev_client_hotplug,
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 3fa38d4ac70b..fe9c6d7083ea 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -168,6 +168,10 @@ void drm_client_release(struct drm_client_dev *client)
>   
>   	drm_client_modeset_free(client);
>   	drm_client_close(client);
> +
> +	if (client->funcs && client->funcs->free)
> +		client->funcs->free(client);
> +
>   	drm_dev_put(dev);
>   }
>   EXPORT_SYMBOL(drm_client_release);
> diff --git a/drivers/gpu/drm/drm_fbdev_dma.c b/drivers/gpu/drm/drm_fbdev_dma.c
> index 8bd626ef16c7..c6196293e424 100644
> --- a/drivers/gpu/drm/drm_fbdev_dma.c
> +++ b/drivers/gpu/drm/drm_fbdev_dma.c
> @@ -57,8 +57,6 @@ static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
>   	drm_client_buffer_vunmap(fb_helper->buffer);
>   	drm_client_framebuffer_delete(fb_helper->buffer);
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops drm_fbdev_dma_fb_ops = {
> @@ -92,8 +90,6 @@ static void drm_fbdev_dma_shadowed_fb_destroy(struct fb_info *info)
>   	drm_client_buffer_vunmap(fb_helper->buffer);
>   	drm_client_framebuffer_delete(fb_helper->buffer);
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
> diff --git a/drivers/gpu/drm/drm_fbdev_shmem.c b/drivers/gpu/drm/drm_fbdev_shmem.c
> index 1e827bf8b815..51573058df6f 100644
> --- a/drivers/gpu/drm/drm_fbdev_shmem.c
> +++ b/drivers/gpu/drm/drm_fbdev_shmem.c
> @@ -65,8 +65,6 @@ static void drm_fbdev_shmem_fb_destroy(struct fb_info *info)
>   	drm_client_buffer_vunmap(fb_helper->buffer);
>   	drm_client_framebuffer_delete(fb_helper->buffer);
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops drm_fbdev_shmem_fb_ops = {
> diff --git a/drivers/gpu/drm/drm_fbdev_ttm.c b/drivers/gpu/drm/drm_fbdev_ttm.c
> index 85feb55bba11..ccf460fbc1f0 100644
> --- a/drivers/gpu/drm/drm_fbdev_ttm.c
> +++ b/drivers/gpu/drm/drm_fbdev_ttm.c
> @@ -53,8 +53,6 @@ static void drm_fbdev_ttm_fb_destroy(struct fb_info *info)
>   	drm_client_framebuffer_delete(fb_helper->buffer);
>   
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops drm_fbdev_ttm_fb_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> index 93de25b77e68..a3bd21a827ad 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> @@ -42,8 +42,6 @@ static void exynos_drm_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb);
>   
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops exynos_drm_fb_ops = {
> diff --git a/drivers/gpu/drm/gma500/fbdev.c b/drivers/gpu/drm/gma500/fbdev.c
> index a6af21514cff..bc92fa24a1e2 100644
> --- a/drivers/gpu/drm/gma500/fbdev.c
> +++ b/drivers/gpu/drm/gma500/fbdev.c
> @@ -84,9 +84,6 @@ static void psb_fbdev_fb_destroy(struct fb_info *info)
>   	drm_gem_object_put(obj);
>   
>   	drm_client_release(&fb_helper->client);
> -
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops psb_fbdev_fb_ops = {
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 3fbdf75415cc..d5f26c8bb102 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -146,8 +146,6 @@ static void intel_fbdev_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb_helper->fb);
>   
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   __diag_push();
> diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
> index b5969374d53f..aad6fb77f0de 100644
> --- a/drivers/gpu/drm/msm/msm_fbdev.c
> +++ b/drivers/gpu/drm/msm/msm_fbdev.c
> @@ -52,8 +52,6 @@ static void msm_fbdev_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb);
>   
>   	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>   }
>   
>   static const struct fb_ops msm_fb_ops = {
> diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> index 948af7ec1130..b5df2923d2a6 100644
> --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
> +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> @@ -103,8 +103,6 @@ static void omap_fbdev_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb);
>   
>   	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>   }
>   
>   /*
> diff --git a/drivers/gpu/drm/radeon/radeon_fbdev.c b/drivers/gpu/drm/radeon/radeon_fbdev.c
> index dc81b0c2dbff..4df6c9167bf0 100644
> --- a/drivers/gpu/drm/radeon/radeon_fbdev.c
> +++ b/drivers/gpu/drm/radeon/radeon_fbdev.c
> @@ -184,8 +184,6 @@ static void radeon_fbdev_fb_destroy(struct fb_info *info)
>   	radeon_fbdev_destroy_pinned_object(gobj);
>   
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops radeon_fbdev_fb_ops = {
> diff --git a/drivers/gpu/drm/tegra/fbdev.c b/drivers/gpu/drm/tegra/fbdev.c
> index 1b70f5e164af..91aece6f34e0 100644
> --- a/drivers/gpu/drm/tegra/fbdev.c
> +++ b/drivers/gpu/drm/tegra/fbdev.c
> @@ -53,8 +53,6 @@ static void tegra_fbdev_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb);
>   
>   	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>   }
>   
>   static const struct fb_ops tegra_fb_ops = {
> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
> index bdd845e383ef..eecb8d6e15c7 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -28,6 +28,16 @@ struct drm_client_funcs {
>   	 */
>   	struct module *owner;
>   
> +	/**
> +	 * @free:
> +	 *
> +	 * Called when the client gets unregistered. Implementations should
> +	 * release all client-specific data and free the memory.
> +	 *
> +	 * This callback is optional.
> +	 */
> +	void (*free)(struct drm_client_dev *client);
> +
>   	/**
>   	 * @unregister:
>   	 *

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

Re: [PATCH 1/4] drm/client: Add client free callback to unprepare fb_helper

[Thomas Zimmermann]

Am 09.10.25 um 15:16 schrieb Thomas Zimmermann:
> Add free callback to struct drm_client_funcs. Invoke function to
> free the client memory as part of the release process. Implement
> free for fbdev emulation.
>
> Fbdev emulation allocates and prepares client memory in
> drm_fbdev_client_setup(). The release happens in fb_destroy from
> struct fb_ops. Multiple implementations of this callback exist in
> the various drivers that provide fbdev implementation. Each of them
> needs to follow the implementation details of the fbdev setup code.
>
> Adding a free callback for the client puts the unprepare and release
> of the fbdev client in a single place.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Acked-by: Alex Deucher <alexander.deucher@amd.com>

via irc

https://people.freedesktop.org/~cbrill/dri-log/?channel=radeon&highlight_names=&date=2025-10-23&show_html=true

> ---
>   drivers/gpu/drm/armada/armada_fbdev.c      |  2 --
>   drivers/gpu/drm/clients/drm_fbdev_client.c | 17 +++++++++++++++--
>   drivers/gpu/drm/drm_client.c               |  4 ++++
>   drivers/gpu/drm/drm_fbdev_dma.c            |  4 ----
>   drivers/gpu/drm/drm_fbdev_shmem.c          |  2 --
>   drivers/gpu/drm/drm_fbdev_ttm.c            |  2 --
>   drivers/gpu/drm/exynos/exynos_drm_fbdev.c  |  2 --
>   drivers/gpu/drm/gma500/fbdev.c             |  3 ---
>   drivers/gpu/drm/i915/display/intel_fbdev.c |  2 --
>   drivers/gpu/drm/msm/msm_fbdev.c            |  2 --
>   drivers/gpu/drm/omapdrm/omap_fbdev.c       |  2 --
>   drivers/gpu/drm/radeon/radeon_fbdev.c      |  2 --
>   drivers/gpu/drm/tegra/fbdev.c              |  2 --
>   include/drm/drm_client.h                   | 10 ++++++++++
>   14 files changed, 29 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/armada/armada_fbdev.c b/drivers/gpu/drm/armada/armada_fbdev.c
> index cb53cc91bafb..22e2081bfa04 100644
> --- a/drivers/gpu/drm/armada/armada_fbdev.c
> +++ b/drivers/gpu/drm/armada/armada_fbdev.c
> @@ -28,8 +28,6 @@ static void armada_fbdev_fb_destroy(struct fb_info *info)
>   	fbh->fb->funcs->destroy(fbh->fb);
>   
>   	drm_client_release(&fbh->client);
> -	drm_fb_helper_unprepare(fbh);
> -	kfree(fbh);
>   }
>   
>   static const struct fb_ops armada_fb_ops = {
> diff --git a/drivers/gpu/drm/clients/drm_fbdev_client.c b/drivers/gpu/drm/clients/drm_fbdev_client.c
> index f894ba52bdb5..5336accab1b6 100644
> --- a/drivers/gpu/drm/clients/drm_fbdev_client.c
> +++ b/drivers/gpu/drm/clients/drm_fbdev_client.c
> @@ -13,16 +13,28 @@
>    * struct drm_client_funcs
>    */
>   
> +static void drm_fbdev_client_free(struct drm_client_dev *client)
> +{
> +	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
> +
> +	drm_fb_helper_unprepare(fb_helper);
> +	kfree(fb_helper);
> +}
> +
>   static void drm_fbdev_client_unregister(struct drm_client_dev *client)
>   {
>   	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
>   
>   	if (fb_helper->info) {
> +		/*
> +		 * Fully probed framebuffer device
> +		 */
>   		drm_fb_helper_unregister_info(fb_helper);
>   	} else {
> +		/*
> +		 * Partially initialized client, no framebuffer device yet
> +		 */
>   		drm_client_release(&fb_helper->client);
> -		drm_fb_helper_unprepare(fb_helper);
> -		kfree(fb_helper);
>   	}
>   }
>   
> @@ -88,6 +100,7 @@ static int drm_fbdev_client_resume(struct drm_client_dev *client, bool holds_con
>   
>   static const struct drm_client_funcs drm_fbdev_client_funcs = {
>   	.owner		= THIS_MODULE,
> +	.free		= drm_fbdev_client_free,
>   	.unregister	= drm_fbdev_client_unregister,
>   	.restore	= drm_fbdev_client_restore,
>   	.hotplug	= drm_fbdev_client_hotplug,
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 3fa38d4ac70b..fe9c6d7083ea 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -168,6 +168,10 @@ void drm_client_release(struct drm_client_dev *client)
>   
>   	drm_client_modeset_free(client);
>   	drm_client_close(client);
> +
> +	if (client->funcs && client->funcs->free)
> +		client->funcs->free(client);
> +
>   	drm_dev_put(dev);
>   }
>   EXPORT_SYMBOL(drm_client_release);
> diff --git a/drivers/gpu/drm/drm_fbdev_dma.c b/drivers/gpu/drm/drm_fbdev_dma.c
> index 8bd626ef16c7..c6196293e424 100644
> --- a/drivers/gpu/drm/drm_fbdev_dma.c
> +++ b/drivers/gpu/drm/drm_fbdev_dma.c
> @@ -57,8 +57,6 @@ static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
>   	drm_client_buffer_vunmap(fb_helper->buffer);
>   	drm_client_framebuffer_delete(fb_helper->buffer);
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops drm_fbdev_dma_fb_ops = {
> @@ -92,8 +90,6 @@ static void drm_fbdev_dma_shadowed_fb_destroy(struct fb_info *info)
>   	drm_client_buffer_vunmap(fb_helper->buffer);
>   	drm_client_framebuffer_delete(fb_helper->buffer);
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
> diff --git a/drivers/gpu/drm/drm_fbdev_shmem.c b/drivers/gpu/drm/drm_fbdev_shmem.c
> index 1e827bf8b815..51573058df6f 100644
> --- a/drivers/gpu/drm/drm_fbdev_shmem.c
> +++ b/drivers/gpu/drm/drm_fbdev_shmem.c
> @@ -65,8 +65,6 @@ static void drm_fbdev_shmem_fb_destroy(struct fb_info *info)
>   	drm_client_buffer_vunmap(fb_helper->buffer);
>   	drm_client_framebuffer_delete(fb_helper->buffer);
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops drm_fbdev_shmem_fb_ops = {
> diff --git a/drivers/gpu/drm/drm_fbdev_ttm.c b/drivers/gpu/drm/drm_fbdev_ttm.c
> index 85feb55bba11..ccf460fbc1f0 100644
> --- a/drivers/gpu/drm/drm_fbdev_ttm.c
> +++ b/drivers/gpu/drm/drm_fbdev_ttm.c
> @@ -53,8 +53,6 @@ static void drm_fbdev_ttm_fb_destroy(struct fb_info *info)
>   	drm_client_framebuffer_delete(fb_helper->buffer);
>   
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops drm_fbdev_ttm_fb_ops = {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> index 93de25b77e68..a3bd21a827ad 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> @@ -42,8 +42,6 @@ static void exynos_drm_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb);
>   
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops exynos_drm_fb_ops = {
> diff --git a/drivers/gpu/drm/gma500/fbdev.c b/drivers/gpu/drm/gma500/fbdev.c
> index a6af21514cff..bc92fa24a1e2 100644
> --- a/drivers/gpu/drm/gma500/fbdev.c
> +++ b/drivers/gpu/drm/gma500/fbdev.c
> @@ -84,9 +84,6 @@ static void psb_fbdev_fb_destroy(struct fb_info *info)
>   	drm_gem_object_put(obj);
>   
>   	drm_client_release(&fb_helper->client);
> -
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops psb_fbdev_fb_ops = {
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 3fbdf75415cc..d5f26c8bb102 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> @@ -146,8 +146,6 @@ static void intel_fbdev_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb_helper->fb);
>   
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   __diag_push();
> diff --git a/drivers/gpu/drm/msm/msm_fbdev.c b/drivers/gpu/drm/msm/msm_fbdev.c
> index b5969374d53f..aad6fb77f0de 100644
> --- a/drivers/gpu/drm/msm/msm_fbdev.c
> +++ b/drivers/gpu/drm/msm/msm_fbdev.c
> @@ -52,8 +52,6 @@ static void msm_fbdev_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb);
>   
>   	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>   }
>   
>   static const struct fb_ops msm_fb_ops = {
> diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> index 948af7ec1130..b5df2923d2a6 100644
> --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c
> +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c
> @@ -103,8 +103,6 @@ static void omap_fbdev_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb);
>   
>   	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>   }
>   
>   /*
> diff --git a/drivers/gpu/drm/radeon/radeon_fbdev.c b/drivers/gpu/drm/radeon/radeon_fbdev.c
> index dc81b0c2dbff..4df6c9167bf0 100644
> --- a/drivers/gpu/drm/radeon/radeon_fbdev.c
> +++ b/drivers/gpu/drm/radeon/radeon_fbdev.c
> @@ -184,8 +184,6 @@ static void radeon_fbdev_fb_destroy(struct fb_info *info)
>   	radeon_fbdev_destroy_pinned_object(gobj);
>   
>   	drm_client_release(&fb_helper->client);
> -	drm_fb_helper_unprepare(fb_helper);
> -	kfree(fb_helper);
>   }
>   
>   static const struct fb_ops radeon_fbdev_fb_ops = {
> diff --git a/drivers/gpu/drm/tegra/fbdev.c b/drivers/gpu/drm/tegra/fbdev.c
> index 1b70f5e164af..91aece6f34e0 100644
> --- a/drivers/gpu/drm/tegra/fbdev.c
> +++ b/drivers/gpu/drm/tegra/fbdev.c
> @@ -53,8 +53,6 @@ static void tegra_fbdev_fb_destroy(struct fb_info *info)
>   	drm_framebuffer_remove(fb);
>   
>   	drm_client_release(&helper->client);
> -	drm_fb_helper_unprepare(helper);
> -	kfree(helper);
>   }
>   
>   static const struct fb_ops tegra_fb_ops = {
> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
> index bdd845e383ef..eecb8d6e15c7 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -28,6 +28,16 @@ struct drm_client_funcs {
>   	 */
>   	struct module *owner;
>   
> +	/**
> +	 * @free:
> +	 *
> +	 * Called when the client gets unregistered. Implementations should
> +	 * release all client-specific data and free the memory.
> +	 *
> +	 * This callback is optional.
> +	 */
> +	void (*free)(struct drm_client_dev *client);
> +
>   	/**
>   	 * @unregister:
>   	 *

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)