[PATCH 0/5] drm/exynos: Convert fbdev to DRM client

[PATCH 0/5] drm/exynos: Convert fbdev to DRM client

[Thomas Zimmermann]

Convert exynos' fbdev code to struct drm_client. Replaces the current
ad-hoc integration. The conversion includes a number of cleanups. As
with most other drivers' fbdev emulation, fbdev in exynos is now just
another DRM client that runs after the DRM device has been registered.

Once all drivers' fbdev emulation has been converted to struct drm_client,
we can attempt to add additional in-kernel clients. A DRM-based dmesg
log or a bootsplash are commonly mentioned. DRM can then switch easily
among the existing clients if/when required.

I did the conversion from similar experience with other drivers. But I
don't have the hardware to test this. Any testing is welcome.

Thomas Zimmermann (5):
  drm/exynos: Remove exynos_gem from struct exynos_drm_fbdev
  drm/exynos: Remove struct exynos_drm_fbdev
  drm/exynos: Remove fb_helper from struct exynos_drm_private
  drm/exynos: Initialize fbdev DRM client
  drm/exynos: Implement fbdev emulation as in-kernel client

 drivers/gpu/drm/exynos/exynos_drm_drv.c   |  13 +-
 drivers/gpu/drm/exynos/exynos_drm_drv.h   |   2 -
 drivers/gpu/drm/exynos/exynos_drm_fb.c    |   2 -
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 174 +++++++++++-----------
 drivers/gpu/drm/exynos/exynos_drm_fbdev.h |  20 +--
 5 files changed, 94 insertions(+), 117 deletions(-)

-- 
2.40.0

[PATCH 1/5] drm/exynos: Remove exynos_gem from struct exynos_drm_fbdev

[Thomas Zimmermann]

Fbdev's framebuffer stores a pointer to the GEM object. Remove
struct exynos_drm_fbdev.exynos_gem, which contains the same value.
No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index 4929ffe5a09a..f11895d32982 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -16,6 +16,7 @@
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_prime.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/exynos_drm.h>
@@ -32,17 +33,14 @@
 
 struct exynos_drm_fbdev {
 	struct drm_fb_helper	drm_fb_helper;
-	struct exynos_drm_gem	*exynos_gem;
 };
 
-static int exynos_drm_fb_mmap(struct fb_info *info,
-			struct vm_area_struct *vma)
+static int exynos_drm_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 {
 	struct drm_fb_helper *helper = info->par;
-	struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(helper);
-	struct exynos_drm_gem *exynos_gem = exynos_fbd->exynos_gem;
+	struct drm_gem_object *obj = drm_gem_fb_get_obj(helper->fb, 0);
 
-	return drm_gem_prime_mmap(&exynos_gem->base, vma);
+	return drm_gem_prime_mmap(obj, vma);
 }
 
 static const struct fb_ops exynos_drm_fb_ops = {
@@ -89,7 +87,6 @@ static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
 static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 				    struct drm_fb_helper_surface_size *sizes)
 {
-	struct exynos_drm_fbdev *exynos_fbdev = to_exynos_fbdev(helper);
 	struct exynos_drm_gem *exynos_gem;
 	struct drm_device *dev = helper->dev;
 	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
@@ -113,8 +110,6 @@ static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 	if (IS_ERR(exynos_gem))
 		return PTR_ERR(exynos_gem);
 
-	exynos_fbdev->exynos_gem = exynos_gem;
-
 	helper->fb =
 		exynos_drm_framebuffer_init(dev, &mode_cmd, &exynos_gem, 1);
 	if (IS_ERR(helper->fb)) {
-- 
2.40.0

[PATCH 2/5] drm/exynos: Remove struct exynos_drm_fbdev

[Thomas Zimmermann]

Remove struct exynos_drm_fbdev, which is an empty wrapper around
struct drm_fb_helper. Use the latter directly. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index f11895d32982..e7059850baa2 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -28,13 +28,6 @@
 #define MAX_CONNECTOR		4
 #define PREFERRED_BPP		32
 
-#define to_exynos_fbdev(x)	container_of(x, struct exynos_drm_fbdev,\
-				drm_fb_helper)
-
-struct exynos_drm_fbdev {
-	struct drm_fb_helper	drm_fb_helper;
-};
-
 static int exynos_drm_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 {
 	struct drm_fb_helper *helper = info->par;
@@ -144,7 +137,6 @@ static const struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
 
 int exynos_drm_fbdev_init(struct drm_device *dev)
 {
-	struct exynos_drm_fbdev *fbdev;
 	struct exynos_drm_private *private = dev->dev_private;
 	struct drm_fb_helper *helper;
 	int ret;
@@ -152,11 +144,11 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
 	if (!dev->mode_config.num_crtc)
 		return 0;
 
-	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
-	if (!fbdev)
+	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
+	if (!helper)
 		return -ENOMEM;
 
-	private->fb_helper = helper = &fbdev->drm_fb_helper;
+	private->fb_helper = helper;
 
 	drm_fb_helper_prepare(dev, helper, PREFERRED_BPP, &exynos_drm_fb_helper_funcs);
 
@@ -181,7 +173,7 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
 err_init:
 	drm_fb_helper_unprepare(helper);
 	private->fb_helper = NULL;
-	kfree(fbdev);
+	kfree(helper);
 
 	return ret;
 }
@@ -206,16 +198,13 @@ static void exynos_drm_fbdev_destroy(struct drm_device *dev,
 void exynos_drm_fbdev_fini(struct drm_device *dev)
 {
 	struct exynos_drm_private *private = dev->dev_private;
-	struct exynos_drm_fbdev *fbdev;
 
 	if (!private || !private->fb_helper)
 		return;
 
-	fbdev = to_exynos_fbdev(private->fb_helper);
-
 	exynos_drm_fbdev_destroy(dev, private->fb_helper);
 	drm_fb_helper_unprepare(private->fb_helper);
-	kfree(fbdev);
+	kfree(private->fb_helper);
 	private->fb_helper = NULL;
 }
 
-- 
2.40.0

[PATCH 3/5] drm/exynos: Remove fb_helper from struct exynos_drm_private

[Thomas Zimmermann]

The DRM device stores a pointer to the fbdev helper. Remove struct
exynos_drm_private.fb_helper, which contains the same value. No
functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/exynos/exynos_drm_drv.h   |  2 --
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 15 +++++----------
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.h b/drivers/gpu/drm/exynos/exynos_drm_drv.h
index 6ae9056e7a18..81d501efd013 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.h
@@ -197,8 +197,6 @@ struct drm_exynos_file_private {
  * @wait: wait an atomic commit to finish
  */
 struct exynos_drm_private {
-	struct drm_fb_helper *fb_helper;
-
 	struct device *g2d_dev;
 	struct device *dma_dev;
 	void *mapping;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index e7059850baa2..81f909cb5c9b 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -137,7 +137,6 @@ static const struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
 
 int exynos_drm_fbdev_init(struct drm_device *dev)
 {
-	struct exynos_drm_private *private = dev->dev_private;
 	struct drm_fb_helper *helper;
 	int ret;
 
@@ -148,8 +147,6 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
 	if (!helper)
 		return -ENOMEM;
 
-	private->fb_helper = helper;
-
 	drm_fb_helper_prepare(dev, helper, PREFERRED_BPP, &exynos_drm_fb_helper_funcs);
 
 	ret = drm_fb_helper_init(dev, helper);
@@ -172,7 +169,6 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
 	drm_fb_helper_fini(helper);
 err_init:
 	drm_fb_helper_unprepare(helper);
-	private->fb_helper = NULL;
 	kfree(helper);
 
 	return ret;
@@ -197,14 +193,13 @@ static void exynos_drm_fbdev_destroy(struct drm_device *dev,
 
 void exynos_drm_fbdev_fini(struct drm_device *dev)
 {
-	struct exynos_drm_private *private = dev->dev_private;
+	struct drm_fb_helper *fb_helper = dev->fb_helper;
 
-	if (!private || !private->fb_helper)
+	if (!fb_helper)
 		return;
 
-	exynos_drm_fbdev_destroy(dev, private->fb_helper);
-	drm_fb_helper_unprepare(private->fb_helper);
-	kfree(private->fb_helper);
-	private->fb_helper = NULL;
+	exynos_drm_fbdev_destroy(dev, fb_helper);
+	drm_fb_helper_unprepare(fb_helper);
+	kfree(fb_helper);
 }
 
-- 
2.40.0

[PATCH 4/5] drm/exynos: Initialize fbdev DRM client

[Thomas Zimmermann]

Initialize the fbdev client in the fbdev code with empty helper
functions. Also clean up the client. The helpers will later
implement various functionality of the DRM client. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 35 +++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index 81f909cb5c9b..d1de49530c48 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -135,6 +135,30 @@ static const struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
 	.fb_probe =	exynos_drm_fbdev_create,
 };
 
+/*
+ * struct drm_client
+ */
+
+static void exynos_drm_fbdev_client_unregister(struct drm_client_dev *client)
+{ }
+
+static int exynos_drm_fbdev_client_restore(struct drm_client_dev *client)
+{
+	return 0;
+}
+
+static int exynos_drm_fbdev_client_hotplug(struct drm_client_dev *client)
+{
+	return 0;
+}
+
+static const struct drm_client_funcs exynos_drm_fbdev_client_funcs = {
+	.owner		= THIS_MODULE,
+	.unregister	= exynos_drm_fbdev_client_unregister,
+	.restore	= exynos_drm_fbdev_client_restore,
+	.hotplug	= exynos_drm_fbdev_client_hotplug,
+};
+
 int exynos_drm_fbdev_init(struct drm_device *dev)
 {
 	struct drm_fb_helper *helper;
@@ -149,11 +173,15 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
 
 	drm_fb_helper_prepare(dev, helper, PREFERRED_BPP, &exynos_drm_fb_helper_funcs);
 
+	ret = drm_client_init(dev, &helper->client, "exynos-fbdev", &exynos_drm_fbdev_client_funcs);
+	if (ret)
+		goto err_drm_fb_helper_unprepare;
+
 	ret = drm_fb_helper_init(dev, helper);
 	if (ret < 0) {
 		DRM_DEV_ERROR(dev->dev,
 			      "failed to initialize drm fb helper.\n");
-		goto err_init;
+		goto err_drm_client_release;
 	}
 
 	ret = drm_fb_helper_initial_config(helper);
@@ -167,7 +195,9 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
 
 err_setup:
 	drm_fb_helper_fini(helper);
-err_init:
+err_drm_client_release:
+	drm_client_release(&helper->client);
+err_drm_fb_helper_unprepare:
 	drm_fb_helper_unprepare(helper);
 	kfree(helper);
 
@@ -199,6 +229,7 @@ void exynos_drm_fbdev_fini(struct drm_device *dev)
 		return;
 
 	exynos_drm_fbdev_destroy(dev, fb_helper);
+	drm_client_release(&fb_helper->client);
 	drm_fb_helper_unprepare(fb_helper);
 	kfree(fb_helper);
 }
-- 
2.40.0

[PATCH 5/5] drm/exynos: Implement fbdev emulation as in-kernel client

[Thomas Zimmermann]

Move code from ad-hoc fbdev callbacks into DRM client functions
and remove the old callbacks. The functions instruct the client
to poll for changed output or restore the display. The DRM core
calls both, the old callbacks and the new client helpers, from
the same places. The new functions perform the same operation as
before, so there's no change in functionality.

Replace all code that initializes or releases fbdev emulation
throughout the driver. Instead initialize the fbdev client by a
single call to exynos_fbdev_setup() after exynos has registered its
DRM device. As in most drivers, exynos' fbdev emulation now acts
like a regular DRM client.

The fbdev client setup consists of the initial preparation and the
hot-plugging of the display. The latter creates the fbdev device
and sets up the fbdev framebuffer. The setup performs display
hot-plugging once. If no display can be detected, DRM probe helpers
re-run the detection on each hotplug event.

A call to drm_dev_unregister() releases the client automatically.
No further action is required within exynos. If the fbdev framebuffer
has been fully set up, struct fb_ops.fb_destroy implements the
release. For partially initialized emulation, the fbdev client
reverts the initial setup.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/exynos/exynos_drm_drv.c   |  13 +-
 drivers/gpu/drm/exynos/exynos_drm_fb.c    |   2 -
 drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 150 +++++++++++-----------
 drivers/gpu/drm/exynos/exynos_drm_fbdev.h |  20 +--
 4 files changed, 77 insertions(+), 108 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index 16c539657f73..6b73fb7a83c3 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -16,7 +16,6 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_drv.h>
-#include <drm/drm_fb_helper.h>
 #include <drm/drm_file.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_ioctl.h>
@@ -108,7 +107,6 @@ static const struct drm_driver exynos_drm_driver = {
 	.driver_features	= DRIVER_MODESET | DRIVER_GEM
 				  | DRIVER_ATOMIC | DRIVER_RENDER,
 	.open			= exynos_drm_open,
-	.lastclose		= drm_fb_helper_lastclose,
 	.postclose		= exynos_drm_postclose,
 	.dumb_create		= exynos_drm_gem_dumb_create,
 	.prime_handle_to_fd	= drm_gem_prime_handle_to_fd,
@@ -288,19 +286,15 @@ static int exynos_drm_bind(struct device *dev)
 	/* init kms poll for handling hpd */
 	drm_kms_helper_poll_init(drm);
 
-	ret = exynos_drm_fbdev_init(drm);
-	if (ret)
-		goto err_cleanup_poll;
-
 	/* register the DRM device */
 	ret = drm_dev_register(drm, 0);
 	if (ret < 0)
-		goto err_cleanup_fbdev;
+		goto err_cleanup_poll;
+
+	exynos_drm_fbdev_setup(drm);
 
 	return 0;
 
-err_cleanup_fbdev:
-	exynos_drm_fbdev_fini(drm);
 err_cleanup_poll:
 	drm_kms_helper_poll_fini(drm);
 err_unbind_all:
@@ -321,7 +315,6 @@ static void exynos_drm_unbind(struct device *dev)
 
 	drm_dev_unregister(drm);
 
-	exynos_drm_fbdev_fini(drm);
 	drm_kms_helper_poll_fini(drm);
 
 	component_unbind_all(drm->dev, drm);
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fb.c b/drivers/gpu/drm/exynos/exynos_drm_fb.c
index 97f2dee2db29..fc1c5608db96 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fb.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fb.c
@@ -11,7 +11,6 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
-#include <drm/drm_fb_helper.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_framebuffer_helper.h>
@@ -157,7 +156,6 @@ static struct drm_mode_config_helper_funcs exynos_drm_mode_config_helpers = {
 
 static const struct drm_mode_config_funcs exynos_drm_mode_config_funcs = {
 	.fb_create = exynos_user_fb_create,
-	.output_poll_changed = drm_fb_helper_output_poll_changed,
 	.atomic_check = drm_atomic_helper_check,
 	.atomic_commit = drm_atomic_helper_commit,
 };
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
index d1de49530c48..ea4b3d248aac 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
@@ -8,17 +8,12 @@
  *	Seung-Woo Kim <sw0312.kim@samsung.com>
  */
 
-#include <linux/console.h>
-#include <linux/dma-mapping.h>
-#include <linux/vmalloc.h>
-
-#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_drv.h>
 #include <drm/drm_fb_helper.h>
-#include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_prime.h>
-#include <drm/drm_probe_helper.h>
 #include <drm/exynos_drm.h>
 
 #include "exynos_drm_drv.h"
@@ -36,6 +31,20 @@ static int exynos_drm_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
 	return drm_gem_prime_mmap(obj, vma);
 }
 
+static void exynos_drm_fb_destroy(struct fb_info *info)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_framebuffer *fb = fb_helper->fb;
+
+	drm_fb_helper_fini(fb_helper);
+
+	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 = {
 	.owner		= THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
@@ -45,6 +54,7 @@ static const struct fb_ops exynos_drm_fb_ops = {
 	.fb_fillrect	= drm_fb_helper_cfb_fillrect,
 	.fb_copyarea	= drm_fb_helper_cfb_copyarea,
 	.fb_imageblit	= drm_fb_helper_cfb_imageblit,
+	.fb_destroy	= exynos_drm_fb_destroy,
 };
 
 static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
@@ -115,19 +125,13 @@ static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 	if (ret < 0)
 		goto err_destroy_framebuffer;
 
-	return ret;
+	return 0;
 
 err_destroy_framebuffer:
 	drm_framebuffer_cleanup(helper->fb);
+	helper->fb = NULL;
 err_destroy_gem:
 	exynos_drm_gem_destroy(exynos_gem);
-
-	/*
-	 * if failed, all resources allocated above would be released by
-	 * drm_mode_config_cleanup() when drm_load() had been called prior
-	 * to any specific driver such as fimd or hdmi driver.
-	 */
-
 	return ret;
 }
 
@@ -140,16 +144,52 @@ static const struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
  */
 
 static void exynos_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) {
+		drm_fb_helper_unregister_info(fb_helper);
+	} else {
+		drm_client_release(&fb_helper->client);
+		drm_fb_helper_unprepare(fb_helper);
+		kfree(fb_helper);
+	}
+}
 
 static int exynos_drm_fbdev_client_restore(struct drm_client_dev *client)
 {
+	drm_fb_helper_lastclose(client->dev);
+
 	return 0;
 }
 
 static int exynos_drm_fbdev_client_hotplug(struct drm_client_dev *client)
 {
+	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+	struct drm_device *dev = client->dev;
+	int ret;
+
+	if (dev->fb_helper)
+		return drm_fb_helper_hotplug_event(dev->fb_helper);
+
+	ret = drm_fb_helper_init(dev, fb_helper);
+	if (ret)
+		goto err_drm_err;
+
+	if (!drm_drv_uses_atomic_modeset(dev))
+		drm_helper_disable_unused_functions(dev);
+
+	ret = drm_fb_helper_initial_config(fb_helper);
+	if (ret)
+		goto err_drm_fb_helper_fini;
+
 	return 0;
+
+err_drm_fb_helper_fini:
+	drm_fb_helper_fini(fb_helper);
+err_drm_err:
+	drm_err(dev, "Failed to setup fbdev emulation (ret=%d)\n", ret);
+	return ret;
 }
 
 static const struct drm_client_funcs exynos_drm_fbdev_client_funcs = {
@@ -159,78 +199,32 @@ static const struct drm_client_funcs exynos_drm_fbdev_client_funcs = {
 	.hotplug	= exynos_drm_fbdev_client_hotplug,
 };
 
-int exynos_drm_fbdev_init(struct drm_device *dev)
+void exynos_drm_fbdev_setup(struct drm_device *dev)
 {
-	struct drm_fb_helper *helper;
+	struct drm_fb_helper *fb_helper;
 	int ret;
 
-	if (!dev->mode_config.num_crtc)
-		return 0;
+	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
+	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
 
-	helper = kzalloc(sizeof(*helper), GFP_KERNEL);
-	if (!helper)
-		return -ENOMEM;
-
-	drm_fb_helper_prepare(dev, helper, PREFERRED_BPP, &exynos_drm_fb_helper_funcs);
+	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
+	if (!fb_helper)
+		return;
+	drm_fb_helper_prepare(dev, fb_helper, PREFERRED_BPP, &exynos_drm_fb_helper_funcs);
 
-	ret = drm_client_init(dev, &helper->client, "exynos-fbdev", &exynos_drm_fbdev_client_funcs);
+	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &exynos_drm_fbdev_client_funcs);
 	if (ret)
-		goto err_drm_fb_helper_unprepare;
-
-	ret = drm_fb_helper_init(dev, helper);
-	if (ret < 0) {
-		DRM_DEV_ERROR(dev->dev,
-			      "failed to initialize drm fb helper.\n");
-		goto err_drm_client_release;
-	}
-
-	ret = drm_fb_helper_initial_config(helper);
-	if (ret < 0) {
-		DRM_DEV_ERROR(dev->dev,
-			      "failed to set up hw configuration.\n");
-		goto err_setup;
-	}
-
-	return 0;
-
-err_setup:
-	drm_fb_helper_fini(helper);
-err_drm_client_release:
-	drm_client_release(&helper->client);
-err_drm_fb_helper_unprepare:
-	drm_fb_helper_unprepare(helper);
-	kfree(helper);
-
-	return ret;
-}
-
-static void exynos_drm_fbdev_destroy(struct drm_device *dev,
-				      struct drm_fb_helper *fb_helper)
-{
-	struct drm_framebuffer *fb;
+		goto err_drm_client_init;
 
-	/* release drm framebuffer and real buffer */
-	if (fb_helper->fb && fb_helper->fb->funcs) {
-		fb = fb_helper->fb;
-		if (fb)
-			drm_framebuffer_remove(fb);
-	}
-
-	drm_fb_helper_unregister_info(fb_helper);
-
-	drm_fb_helper_fini(fb_helper);
-}
+	ret = exynos_drm_fbdev_client_hotplug(&fb_helper->client);
+	if (ret)
+		drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
 
-void exynos_drm_fbdev_fini(struct drm_device *dev)
-{
-	struct drm_fb_helper *fb_helper = dev->fb_helper;
+	drm_client_register(&fb_helper->client);
 
-	if (!fb_helper)
-		return;
+	return;
 
-	exynos_drm_fbdev_destroy(dev, fb_helper);
-	drm_client_release(&fb_helper->client);
+err_drm_client_init:
 	drm_fb_helper_unprepare(fb_helper);
 	kfree(fb_helper);
 }
-
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.h b/drivers/gpu/drm/exynos/exynos_drm_fbdev.h
index 3b1e98e84580..1e1dea627cd9 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.h
@@ -12,27 +12,11 @@
 #define _EXYNOS_DRM_FBDEV_H_
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-
-int exynos_drm_fbdev_init(struct drm_device *dev);
-void exynos_drm_fbdev_fini(struct drm_device *dev);
-
+void exynos_drm_fbdev_setup(struct drm_device *dev);
 #else
-
-static inline int exynos_drm_fbdev_init(struct drm_device *dev)
-{
-	return 0;
-}
-
-static inline void exynos_drm_fbdev_fini(struct drm_device *dev)
+static inline void exynos_drm_fbdev_setup(struct drm_device *dev)
 {
 }
-
-static inline void exynos_drm_fbdev_restore_mode(struct drm_device *dev)
-{
-}
-
-#define exynos_drm_output_poll_changed (NULL)
-
 #endif
 
 #endif
-- 
2.40.0

Re: [PATCH 0/5] drm/exynos: Convert fbdev to DRM client

[Marek Szyprowski]

On 30.03.2023 09:36, Thomas Zimmermann wrote:
> Convert exynos' fbdev code to struct drm_client. Replaces the current
> ad-hoc integration. The conversion includes a number of cleanups. As
> with most other drivers' fbdev emulation, fbdev in exynos is now just
> another DRM client that runs after the DRM device has been registered.
>
> Once all drivers' fbdev emulation has been converted to struct drm_client,
> we can attempt to add additional in-kernel clients. A DRM-based dmesg
> log or a bootsplash are commonly mentioned. DRM can then switch easily
> among the existing clients if/when required.
>
> I did the conversion from similar experience with other drivers. But I
> don't have the hardware to test this. Any testing is welcome.

Seems to be working fine. Tested with default framebuffer based console 
and simple tool that writes RGB data to /dev/fb0.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>


> Thomas Zimmermann (5):
>    drm/exynos: Remove exynos_gem from struct exynos_drm_fbdev
>    drm/exynos: Remove struct exynos_drm_fbdev
>    drm/exynos: Remove fb_helper from struct exynos_drm_private
>    drm/exynos: Initialize fbdev DRM client
>    drm/exynos: Implement fbdev emulation as in-kernel client
>
>   drivers/gpu/drm/exynos/exynos_drm_drv.c   |  13 +-
>   drivers/gpu/drm/exynos/exynos_drm_drv.h   |   2 -
>   drivers/gpu/drm/exynos/exynos_drm_fb.c    |   2 -
>   drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 174 +++++++++++-----------
>   drivers/gpu/drm/exynos/exynos_drm_fbdev.h |  20 +--
>   5 files changed, 94 insertions(+), 117 deletions(-)
>
Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [PATCH 0/5] drm/exynos: Convert fbdev to DRM client

[Thomas Zimmermann]

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Am 31.03.23 um 12:36 schrieb Marek Szyprowski:
> On 30.03.2023 09:36, Thomas Zimmermann wrote:
>> Convert exynos' fbdev code to struct drm_client. Replaces the current
>> ad-hoc integration. The conversion includes a number of cleanups. As
>> with most other drivers' fbdev emulation, fbdev in exynos is now just
>> another DRM client that runs after the DRM device has been registered.
>>
>> Once all drivers' fbdev emulation has been converted to struct drm_client,
>> we can attempt to add additional in-kernel clients. A DRM-based dmesg
>> log or a bootsplash are commonly mentioned. DRM can then switch easily
>> among the existing clients if/when required.
>>
>> I did the conversion from similar experience with other drivers. But I
>> don't have the hardware to test this. Any testing is welcome.
> 
> Seems to be working fine. Tested with default framebuffer based console
> and simple tool that writes RGB data to /dev/fb0.
> 
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

Thanks a lot for testing.

> 
> 
>> Thomas Zimmermann (5):
>>     drm/exynos: Remove exynos_gem from struct exynos_drm_fbdev
>>     drm/exynos: Remove struct exynos_drm_fbdev
>>     drm/exynos: Remove fb_helper from struct exynos_drm_private
>>     drm/exynos: Initialize fbdev DRM client
>>     drm/exynos: Implement fbdev emulation as in-kernel client
>>
>>    drivers/gpu/drm/exynos/exynos_drm_drv.c   |  13 +-
>>    drivers/gpu/drm/exynos/exynos_drm_drv.h   |   2 -
>>    drivers/gpu/drm/exynos/exynos_drm_fb.c    |   2 -
>>    drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 174 +++++++++++-----------
>>    drivers/gpu/drm/exynos/exynos_drm_fbdev.h |  20 +--
>>    5 files changed, 94 insertions(+), 117 deletions(-)
>>
> Best regards

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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