[PATCH v2 0/8] drm: writeback: clean up writeback connector initialization

[PATCH v2 0/8] drm: writeback: clean up writeback connector initialization

[Dmitry Baryshkov]

Drivers using drm_writeback_connector_init() / _with_encoder() don't
perform cleanup in a manner similar to drmm_writeback_connector_init()
(see drm_writeback_connector_cleanup()). Migrate all existing drivers
to use drmm_writeback_connector_init(), drop
drm_writeback_connector_init() and drm_writeback_connector::encoder
(it's unused afterwards).

This series leaves former drm_writeback_connector_init_with_encoder()
(renamed to drm_writeback_connector_init as a non-managed counterpart
for drmm_writeback_connector_init()). It is supposed to be used by
drivers which can not use drmm functions (like Intel). However I think
it would be better to drop it completely.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
Changes in v2:
- Switched to drm_crtc_mask() where applicable (Louis Chauvet)
- Link to v1: https://lore.kernel.org/r/20250801-wb-drop-encoder-v1-0-824646042f7d@oss.qualcomm.com

---
Dmitry Baryshkov (8):
      drm/amd/display: use drmm_writeback_connector_init()
      drm/komeda: use drmm_writeback_connector_init()
      drm/mali: use drmm_writeback_connector_init()
      drm/msm/dpu: use drmm_writeback_connector_init()
      drm/msm/dpu: use drmm_writeback_connector_init()
      drm/vc4: use drmm_writeback_connector_init()
      drm: writeback: drop excess connector initialization functions
      drm: writeback: rename drm_writeback_connector_init_with_encoder()

 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c  |  2 +-
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c   | 18 ++++--
 .../drm/arm/display/komeda/komeda_wb_connector.c   | 30 ++++++----
 drivers/gpu/drm/arm/malidp_mw.c                    | 25 ++++----
 drivers/gpu/drm/drm_writeback.c                    | 69 +++-------------------
 drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c      | 10 +---
 .../gpu/drm/renesas/rcar-du/rcar_du_writeback.c    | 23 +++++---
 drivers/gpu/drm/vc4/vc4_txp.c                      |  9 ++-
 include/drm/drm_writeback.h                        | 22 +------
 9 files changed, 77 insertions(+), 131 deletions(-)
---
base-commit: cb640b2ca54617f4a9d4d6efd5ff2afd6be11f19
change-id: 20250801-wb-drop-encoder-97a0c75bd5d7

Best regards,
-- 
With best wishes
Dmitry

[PATCH v2 1/8] drm/amd/display: use drmm_writeback_connector_init()

[Dmitry Baryshkov]

Use drmm_plain_encoder_alloc() to allocate simple encoder and
drmm_writeback_connector_init() in order to initialize writeback
connector instance.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c    |  2 +-
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c | 18 +++++++++++++-----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index cd0e2976e268da41f576624c50ef0c76ede67414..0c9d347b1efc804a28fb3095df94e543a19e4159 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -10006,7 +10006,7 @@ static void dm_set_writeback(struct amdgpu_display_manager *dm,
 		return;
 	}
 
-	acrtc = to_amdgpu_crtc(wb_conn->encoder.crtc);
+	acrtc = to_amdgpu_crtc(crtc_state->base.crtc);
 	if (!acrtc) {
 		drm_err(adev_to_drm(adev), "no amdgpu_crtc found\n");
 		kfree(wb_info);
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
index d9527c05fc878ef6916782ff9fde847813938461..80c37487ca77c0494eaf769c5b9a3c53486aa52d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_wb.c
@@ -171,7 +171,6 @@ static const struct drm_encoder_helper_funcs amdgpu_dm_wb_encoder_helper_funcs =
 
 static const struct drm_connector_funcs amdgpu_dm_wb_connector_funcs = {
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = drm_connector_cleanup,
 	.reset = amdgpu_dm_connector_funcs_reset,
 	.atomic_duplicate_state = amdgpu_dm_connector_atomic_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
@@ -190,17 +189,26 @@ int amdgpu_dm_wb_connector_init(struct amdgpu_display_manager *dm,
 	struct dc *dc = dm->dc;
 	struct dc_link *link = dc_get_link_at_index(dc, link_index);
 	int res = 0;
+	struct drm_encoder *encoder;
+
+	encoder = drmm_plain_encoder_alloc(&dm->adev->ddev, NULL,
+					   DRM_MODE_ENCODER_VIRTUAL, NULL);
+	if (IS_ERR(encoder))
+		return PTR_ERR(encoder);
+
+	drm_encoder_helper_add(encoder, &amdgpu_dm_wb_encoder_helper_funcs);
+
+	encoder->possible_crtcs = amdgpu_dm_get_encoder_crtc_mask(dm->adev);
 
 	wbcon->link = link;
 
 	drm_connector_helper_add(&wbcon->base.base, &amdgpu_dm_wb_conn_helper_funcs);
 
-	res = drm_writeback_connector_init(&dm->adev->ddev, &wbcon->base,
+	res = drmm_writeback_connector_init(&dm->adev->ddev, &wbcon->base,
 					    &amdgpu_dm_wb_connector_funcs,
-					    &amdgpu_dm_wb_encoder_helper_funcs,
+					    encoder,
 					    amdgpu_dm_wb_formats,
-					    ARRAY_SIZE(amdgpu_dm_wb_formats),
-					    amdgpu_dm_get_encoder_crtc_mask(dm->adev));
+					    ARRAY_SIZE(amdgpu_dm_wb_formats));
 
 	if (res)
 		return res;

-- 
2.47.2

[PATCH v2 2/8] drm/komeda: use drmm_writeback_connector_init()

[Dmitry Baryshkov]

Use drmm_plain_encoder_alloc() to allocate simple encoder and
drmm_writeback_connector_init() in order to initialize writeback
connector instance.

Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 .../drm/arm/display/komeda/komeda_wb_connector.c   | 30 ++++++++++++----------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c b/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
index 875cdbff18c9dc97e736049feaa8a1fe1bcc82ff..bcc53d4015f1f27181e977272cdcfa35e970fa62 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c
@@ -5,6 +5,7 @@
  *
  */
 #include <drm/drm_framebuffer.h>
+#include <drm/drm_managed.h>
 #include "komeda_dev.h"
 #include "komeda_kms.h"
 
@@ -121,17 +122,10 @@ komeda_wb_connector_fill_modes(struct drm_connector *connector,
 	return 0;
 }
 
-static void komeda_wb_connector_destroy(struct drm_connector *connector)
-{
-	drm_connector_cleanup(connector);
-	kfree(to_kconn(to_wb_conn(connector)));
-}
-
 static const struct drm_connector_funcs komeda_wb_connector_funcs = {
 	.reset			= drm_atomic_helper_connector_reset,
 	.detect			= komeda_wb_connector_detect,
 	.fill_modes		= komeda_wb_connector_fill_modes,
-	.destroy		= komeda_wb_connector_destroy,
 	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
 };
@@ -143,13 +137,15 @@ static int komeda_wb_connector_add(struct komeda_kms_dev *kms,
 	struct komeda_wb_connector *kwb_conn;
 	struct drm_writeback_connector *wb_conn;
 	struct drm_display_info *info;
+	struct drm_encoder *encoder;
+
 	u32 *formats, n_formats = 0;
 	int err;
 
 	if (!kcrtc->master->wb_layer)
 		return 0;
 
-	kwb_conn = kzalloc(sizeof(*kwb_conn), GFP_KERNEL);
+	kwb_conn = drmm_kzalloc(&kms->base, sizeof(*kwb_conn), GFP_KERNEL);
 	if (!kwb_conn)
 		return -ENOMEM;
 
@@ -165,11 +161,19 @@ static int komeda_wb_connector_add(struct komeda_kms_dev *kms,
 		return -ENOMEM;
 	}
 
-	err = drm_writeback_connector_init(&kms->base, wb_conn,
-					   &komeda_wb_connector_funcs,
-					   &komeda_wb_encoder_helper_funcs,
-					   formats, n_formats,
-					   BIT(drm_crtc_index(&kcrtc->base)));
+	encoder = drmm_plain_encoder_alloc(&kms->base, NULL,
+					   DRM_MODE_ENCODER_VIRTUAL, NULL);
+	if (IS_ERR(encoder))
+		return PTR_ERR(encoder);
+
+	drm_encoder_helper_add(encoder, &komeda_wb_encoder_helper_funcs);
+
+	encoder->possible_crtcs = drm_crtc_mask(&kcrtc->base);
+
+	err = drmm_writeback_connector_init(&kms->base, wb_conn,
+					    &komeda_wb_connector_funcs,
+					    encoder,
+					    formats, n_formats);
 	komeda_put_fourcc_list(formats);
 	if (err) {
 		kfree(kwb_conn);

-- 
2.47.2

[PATCH v2 3/8] drm/mali: use drmm_writeback_connector_init()

[Dmitry Baryshkov]

Use drmm_plain_encoder_alloc() to allocate simple encoder and
drmm_writeback_connector_init() in order to initialize writeback
connector instance.

Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/arm/malidp_mw.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c
index 600af5ad81b15d0c30f9f79588f40cca07437ed8..80f7f3474c4494554c6b6fb392e7f396b3b49c83 100644
--- a/drivers/gpu/drm/arm/malidp_mw.c
+++ b/drivers/gpu/drm/arm/malidp_mw.c
@@ -84,11 +84,6 @@ malidp_mw_connector_detect(struct drm_connector *connector, bool force)
 	return connector_status_connected;
 }
 
-static void malidp_mw_connector_destroy(struct drm_connector *connector)
-{
-	drm_connector_cleanup(connector);
-}
-
 static struct drm_connector_state *
 malidp_mw_connector_duplicate_state(struct drm_connector *connector)
 {
@@ -114,7 +109,6 @@ static const struct drm_connector_funcs malidp_mw_connector_funcs = {
 	.reset = malidp_mw_connector_reset,
 	.detect = malidp_mw_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = malidp_mw_connector_destroy,
 	.atomic_duplicate_state = malidp_mw_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 };
@@ -211,6 +205,7 @@ static u32 *get_writeback_formats(struct malidp_drm *malidp, int *n_formats)
 int malidp_mw_connector_init(struct drm_device *drm)
 {
 	struct malidp_drm *malidp = drm_to_malidp(drm);
+	struct drm_encoder *encoder;
 	u32 *formats;
 	int ret, n_formats;
 
@@ -224,11 +219,19 @@ int malidp_mw_connector_init(struct drm_device *drm)
 	if (!formats)
 		return -ENOMEM;
 
-	ret = drm_writeback_connector_init(drm, &malidp->mw_connector,
-					   &malidp_mw_connector_funcs,
-					   &malidp_mw_encoder_helper_funcs,
-					   formats, n_formats,
-					   1 << drm_crtc_index(&malidp->crtc));
+	encoder = drmm_plain_encoder_alloc(drm, NULL, DRM_MODE_ENCODER_VIRTUAL,
+					   NULL);
+	if (IS_ERR(encoder))
+		return PTR_ERR(encoder);
+
+	drm_encoder_helper_add(encoder, &malidp_mw_encoder_helper_funcs);
+
+	encoder->possible_crtcs = drm_crtc_mask(&malidp->crtc);
+
+	ret = drmm_writeback_connector_init(drm, &malidp->mw_connector,
+					    &malidp_mw_connector_funcs,
+					    encoder,
+					    formats, n_formats);
 	kfree(formats);
 	if (ret)
 		return ret;

-- 
2.47.2

[PATCH v2 4/8] drm/msm/dpu: use drmm_writeback_connector_init()

[Dmitry Baryshkov]

Use drmm_plain_encoder_alloc() to allocate simple encoder and
drmm_writeback_connector_init() in order to initialize writeback
connector instance.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
index 8ff496082902b1ee713e806140f39b4730ed256a..cd73468e369a93c50303db2a7d4499bcb17be5d1 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
@@ -80,7 +80,6 @@ static int dpu_wb_conn_atomic_check(struct drm_connector *connector,
 static const struct drm_connector_funcs dpu_wb_conn_funcs = {
 	.reset = drm_atomic_helper_connector_reset,
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = drm_connector_cleanup,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 };
@@ -131,12 +130,9 @@ int dpu_writeback_init(struct drm_device *dev, struct drm_encoder *enc,
 
 	drm_connector_helper_add(&dpu_wb_conn->base.base, &dpu_wb_conn_helper_funcs);
 
-	/* DPU initializes the encoder and sets it up completely for writeback
-	 * cases and hence should use the new API drm_writeback_connector_init_with_encoder
-	 * to initialize the writeback connector
-	 */
-	rc = drm_writeback_connector_init_with_encoder(dev, &dpu_wb_conn->base, enc,
-			&dpu_wb_conn_funcs, format_list, num_formats);
+	rc = drmm_writeback_connector_init(dev, &dpu_wb_conn->base,
+					   &dpu_wb_conn_funcs, enc,
+					   format_list, num_formats);
 
 	if (!rc)
 		dpu_wb_conn->wb_enc = enc;

-- 
2.47.2

[PATCH v2 5/8] drm/msm/dpu: use drmm_writeback_connector_init()

[Dmitry Baryshkov]

Use drmm_plain_encoder_alloc() to allocate simple encoder and
drmm_writeback_connector_init() in order to initialize writeback
connector instance.

Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 .../gpu/drm/renesas/rcar-du/rcar_du_writeback.c    | 23 +++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c b/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
index 8cd37d7b8ae281cbc1fd8cbb243c621174517e23..64cea20d00b38861e22fc53375ab41ae988ceb59 100644
--- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
+++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
@@ -134,7 +134,6 @@ static void rcar_du_wb_conn_reset(struct drm_connector *connector)
 static const struct drm_connector_funcs rcar_du_wb_conn_funcs = {
 	.reset = rcar_du_wb_conn_reset,
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = drm_connector_cleanup,
 	.atomic_duplicate_state = rcar_du_wb_conn_duplicate_state,
 	.atomic_destroy_state = rcar_du_wb_conn_destroy_state,
 };
@@ -202,15 +201,25 @@ int rcar_du_writeback_init(struct rcar_du_device *rcdu,
 {
 	struct drm_writeback_connector *wb_conn = &rcrtc->writeback;
 
+	struct drm_encoder *encoder;
+
+	encoder = drmm_plain_encoder_alloc(&rcdu->ddev, NULL,
+					   DRM_MODE_ENCODER_VIRTUAL, NULL);
+	if (IS_ERR(encoder))
+		return PTR_ERR(encoder);
+
+	drm_encoder_helper_add(encoder, &rcar_du_wb_enc_helper_funcs);
+
+	encoder->possible_crtcs = drm_crtc_mask(&rcrtc->crtc);
+
 	drm_connector_helper_add(&wb_conn->base,
 				 &rcar_du_wb_conn_helper_funcs);
 
-	return drm_writeback_connector_init(&rcdu->ddev, wb_conn,
-					    &rcar_du_wb_conn_funcs,
-					    &rcar_du_wb_enc_helper_funcs,
-					    writeback_formats,
-					    ARRAY_SIZE(writeback_formats),
-					    1 << drm_crtc_index(&rcrtc->crtc));
+	return drmm_writeback_connector_init(&rcdu->ddev, wb_conn,
+					     &rcar_du_wb_conn_funcs,
+					     encoder,
+					     writeback_formats,
+					     ARRAY_SIZE(writeback_formats));
 }
 
 void rcar_du_writeback_setup(struct rcar_du_crtc *rcrtc,

-- 
2.47.2

[PATCH v2 6/8] drm/vc4: use drmm_writeback_connector_init()

[Dmitry Baryshkov]

Use drmm_plain_encoder_alloc() to allocate simple encoder and
drmm_writeback_connector_init() in order to initialize writeback
connector instance.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/vc4/vc4_txp.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_txp.c b/drivers/gpu/drm/vc4/vc4_txp.c
index 42acac05fe47861ced226a4f64661f545e21ddb5..fef4e4ee47cf41d40de47c5201f0349dc36c56bd 100644
--- a/drivers/gpu/drm/vc4/vc4_txp.c
+++ b/drivers/gpu/drm/vc4/vc4_txp.c
@@ -377,7 +377,6 @@ vc4_txp_connector_detect(struct drm_connector *connector, bool force)
 static const struct drm_connector_funcs vc4_txp_connector_funcs = {
 	.detect = vc4_txp_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = drm_connector_cleanup,
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
@@ -601,10 +600,10 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
 
 	drm_connector_helper_add(&txp->connector.base,
 				 &vc4_txp_connector_helper_funcs);
-	ret = drm_writeback_connector_init_with_encoder(drm, &txp->connector,
-							encoder,
-							&vc4_txp_connector_funcs,
-							drm_fmts, ARRAY_SIZE(drm_fmts));
+	ret = drmm_writeback_connector_init(drm, &txp->connector,
+					    &vc4_txp_connector_funcs,
+					    encoder,
+					    drm_fmts, ARRAY_SIZE(drm_fmts));
 	if (ret)
 		return ret;
 

-- 
2.47.2

[PATCH v2 7/8] drm: writeback: drop excess connector initialization functions

[Dmitry Baryshkov]

Now as all drivers have been converted to
drmm_writeback_connector_init(), drop drm_writeback_connector_init() and
drm_writeback_connector::encoder field, they are unused now.

Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/drm_writeback.c | 55 -----------------------------------------
 include/drm/drm_writeback.h     | 18 --------------
 2 files changed, 73 deletions(-)

diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
index 95b8a2e4bda69230591b50be15d14d0b3692373b..1a01df91b2c5868e158d489b782f4c57c61a272c 100644
--- a/drivers/gpu/drm/drm_writeback.c
+++ b/drivers/gpu/drm/drm_writeback.c
@@ -142,61 +142,6 @@ static int create_writeback_properties(struct drm_device *dev)
 	return 0;
 }
 
-static const struct drm_encoder_funcs drm_writeback_encoder_funcs = {
-	.destroy = drm_encoder_cleanup,
-};
-
-/**
- * drm_writeback_connector_init - Initialize a writeback connector and its properties
- * @dev: DRM device
- * @wb_connector: Writeback connector to initialize
- * @con_funcs: Connector funcs vtable
- * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder
- * @formats: Array of supported pixel formats for the writeback engine
- * @n_formats: Length of the formats array
- * @possible_crtcs: possible crtcs for the internal writeback encoder
- *
- * This function creates the writeback-connector-specific properties if they
- * have not been already created, initializes the connector as
- * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
- * values. It will also create an internal encoder associated with the
- * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for
- * the encoder helper.
- *
- * Drivers should always use this function instead of drm_connector_init() to
- * set up writeback connectors.
- *
- * Returns: 0 on success, or a negative error code
- */
-int drm_writeback_connector_init(struct drm_device *dev,
-				 struct drm_writeback_connector *wb_connector,
-				 const struct drm_connector_funcs *con_funcs,
-				 const struct drm_encoder_helper_funcs *enc_helper_funcs,
-				 const u32 *formats, int n_formats,
-				 u32 possible_crtcs)
-{
-	int ret = 0;
-
-	drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
-
-	wb_connector->encoder.possible_crtcs = possible_crtcs;
-
-	ret = drm_encoder_init(dev, &wb_connector->encoder,
-			       &drm_writeback_encoder_funcs,
-			       DRM_MODE_ENCODER_VIRTUAL, NULL);
-	if (ret)
-		return ret;
-
-	ret = drm_writeback_connector_init_with_encoder(dev, wb_connector, &wb_connector->encoder,
-			con_funcs, formats, n_formats);
-
-	if (ret)
-		drm_encoder_cleanup(&wb_connector->encoder);
-
-	return ret;
-}
-EXPORT_SYMBOL(drm_writeback_connector_init);
-
 static void delete_writeback_properties(struct drm_device *dev)
 {
 	if (dev->mode_config.writeback_pixel_formats_property) {
diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
index c380a7b8f55a3616fa070c037d5cc653b0061fe6..879ca103320cc225ffb3687419088361315535fc 100644
--- a/include/drm/drm_writeback.h
+++ b/include/drm/drm_writeback.h
@@ -24,17 +24,6 @@ struct drm_writeback_connector {
 	 */
 	struct drm_connector base;
 
-	/**
-	 * @encoder: Internal encoder used by the connector to fulfill
-	 * the DRM framework requirements. The users of the
-	 * @drm_writeback_connector control the behaviour of the @encoder
-	 * by passing the @enc_funcs parameter to drm_writeback_connector_init()
-	 * function.
-	 * For users of drm_writeback_connector_init_with_encoder(), this field
-	 * is not valid as the encoder is managed within their drivers.
-	 */
-	struct drm_encoder encoder;
-
 	/**
 	 * @pixel_formats_blob_ptr:
 	 *
@@ -148,13 +137,6 @@ drm_connector_to_writeback(struct drm_connector *connector)
 	return container_of(connector, struct drm_writeback_connector, base);
 }
 
-int drm_writeback_connector_init(struct drm_device *dev,
-				 struct drm_writeback_connector *wb_connector,
-				 const struct drm_connector_funcs *con_funcs,
-				 const struct drm_encoder_helper_funcs *enc_helper_funcs,
-				 const u32 *formats, int n_formats,
-				 u32 possible_crtcs);
-
 int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
 				struct drm_writeback_connector *wb_connector,
 				struct drm_encoder *enc,

-- 
2.47.2

[PATCH v2 8/8] drm: writeback: rename drm_writeback_connector_init_with_encoder()

[Dmitry Baryshkov]

Rename drm_writeback_connector_init_with_encoder() to
drm_writeback_connector_init() and adapt its interface to follow
drmm_writeback_connector_init().

Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/drm_writeback.c | 14 +++++++-------
 include/drm/drm_writeback.h     | 10 +++++-----
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
index 1a01df91b2c5868e158d489b782f4c57c61a272c..ec2575c4c21b7449707b0595322e2202a0cf9865 100644
--- a/drivers/gpu/drm/drm_writeback.c
+++ b/drivers/gpu/drm/drm_writeback.c
@@ -235,7 +235,7 @@ static int __drm_writeback_connector_init(struct drm_device *dev,
 }
 
 /**
- * drm_writeback_connector_init_with_encoder - Initialize a writeback connector with
+ * drm_writeback_connector_init - Initialize a writeback connector with
  * a custom encoder
  *
  * @dev: DRM device
@@ -263,11 +263,11 @@ static int __drm_writeback_connector_init(struct drm_device *dev,
  *
  * Returns: 0 on success, or a negative error code
  */
-int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
-					      struct drm_writeback_connector *wb_connector,
-					      struct drm_encoder *enc,
-					      const struct drm_connector_funcs *con_funcs,
-					      const u32 *formats, int n_formats)
+int drm_writeback_connector_init(struct drm_device *dev,
+				 struct drm_writeback_connector *wb_connector,
+				 const struct drm_connector_funcs *con_funcs,
+				 struct drm_encoder *enc,
+				 const u32 *formats, int n_formats)
 {
 	struct drm_connector *connector = &wb_connector->base;
 	int ret;
@@ -284,7 +284,7 @@ int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
 
 	return ret;
 }
-EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder);
+EXPORT_SYMBOL(drm_writeback_connector_init);
 
 /**
  * drm_writeback_connector_cleanup - Cleanup the writeback connector
diff --git a/include/drm/drm_writeback.h b/include/drm/drm_writeback.h
index 879ca103320cc225ffb3687419088361315535fc..958466a05e604b387722610fc11f9e841316d21b 100644
--- a/include/drm/drm_writeback.h
+++ b/include/drm/drm_writeback.h
@@ -137,11 +137,11 @@ drm_connector_to_writeback(struct drm_connector *connector)
 	return container_of(connector, struct drm_writeback_connector, base);
 }
 
-int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
-				struct drm_writeback_connector *wb_connector,
-				struct drm_encoder *enc,
-				const struct drm_connector_funcs *con_funcs, const u32 *formats,
-				int n_formats);
+int drm_writeback_connector_init(struct drm_device *dev,
+				 struct drm_writeback_connector *wb_connector,
+				 const struct drm_connector_funcs *con_funcs,
+				 struct drm_encoder *enc,
+				 const u32 *formats, int n_formats);
 
 int drmm_writeback_connector_init(struct drm_device *dev,
 				  struct drm_writeback_connector *wb_connector,

-- 
2.47.2

Re: [PATCH v2 5/8] drm/msm/dpu: use drmm_writeback_connector_init()

[Jessica Zhang]

On 8/16/2025 8:19 AM, Dmitry Baryshkov wrote:
> Use drmm_plain_encoder_alloc() to allocate simple encoder and
> drmm_writeback_connector_init() in order to initialize writeback
> connector instance.
> 
> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
> Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Hey Dmitry,

Just a heads up, I think the commit message prefix here is incorrect.

Thanks,

Jessica Zhang

> ---
>   .../gpu/drm/renesas/rcar-du/rcar_du_writeback.c    | 23 +++++++++++++++-------
>   1 file changed, 16 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c b/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
> index 8cd37d7b8ae281cbc1fd8cbb243c621174517e23..64cea20d00b38861e22fc53375ab41ae988ceb59 100644
> --- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
> +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_writeback.c
> @@ -134,7 +134,6 @@ static void rcar_du_wb_conn_reset(struct drm_connector *connector)
>   static const struct drm_connector_funcs rcar_du_wb_conn_funcs = {
>   	.reset = rcar_du_wb_conn_reset,
>   	.fill_modes = drm_helper_probe_single_connector_modes,
> -	.destroy = drm_connector_cleanup,
>   	.atomic_duplicate_state = rcar_du_wb_conn_duplicate_state,
>   	.atomic_destroy_state = rcar_du_wb_conn_destroy_state,
>   };
> @@ -202,15 +201,25 @@ int rcar_du_writeback_init(struct rcar_du_device *rcdu,
>   {
>   	struct drm_writeback_connector *wb_conn = &rcrtc->writeback;
>   
> +	struct drm_encoder *encoder;
> +
> +	encoder = drmm_plain_encoder_alloc(&rcdu->ddev, NULL,
> +					   DRM_MODE_ENCODER_VIRTUAL, NULL);
> +	if (IS_ERR(encoder))
> +		return PTR_ERR(encoder);
> +
> +	drm_encoder_helper_add(encoder, &rcar_du_wb_enc_helper_funcs);
> +
> +	encoder->possible_crtcs = drm_crtc_mask(&rcrtc->crtc);
> +
>   	drm_connector_helper_add(&wb_conn->base,
>   				 &rcar_du_wb_conn_helper_funcs);
>   
> -	return drm_writeback_connector_init(&rcdu->ddev, wb_conn,
> -					    &rcar_du_wb_conn_funcs,
> -					    &rcar_du_wb_enc_helper_funcs,
> -					    writeback_formats,
> -					    ARRAY_SIZE(writeback_formats),
> -					    1 << drm_crtc_index(&rcrtc->crtc));
> +	return drmm_writeback_connector_init(&rcdu->ddev, wb_conn,
> +					     &rcar_du_wb_conn_funcs,
> +					     encoder,
> +					     writeback_formats,
> +					     ARRAY_SIZE(writeback_formats));
>   }
>   
>   void rcar_du_writeback_setup(struct rcar_du_crtc *rcrtc,
> 

Re: [PATCH v2 4/8] drm/msm/dpu: use drmm_writeback_connector_init()

[Jessica Zhang]

On 8/16/2025 8:19 AM, Dmitry Baryshkov wrote:
> Use drmm_plain_encoder_alloc() to allocate simple encoder and
> drmm_writeback_connector_init() in order to initialize writeback
> connector instance.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Reviewed-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>

Thanks,

Jessica Zhang

> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 10 +++-------
>   1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
> index 8ff496082902b1ee713e806140f39b4730ed256a..cd73468e369a93c50303db2a7d4499bcb17be5d1 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
> @@ -80,7 +80,6 @@ static int dpu_wb_conn_atomic_check(struct drm_connector *connector,
>   static const struct drm_connector_funcs dpu_wb_conn_funcs = {
>   	.reset = drm_atomic_helper_connector_reset,
>   	.fill_modes = drm_helper_probe_single_connector_modes,
> -	.destroy = drm_connector_cleanup,
>   	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
>   	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>   };
> @@ -131,12 +130,9 @@ int dpu_writeback_init(struct drm_device *dev, struct drm_encoder *enc,
>   
>   	drm_connector_helper_add(&dpu_wb_conn->base.base, &dpu_wb_conn_helper_funcs);
>   
> -	/* DPU initializes the encoder and sets it up completely for writeback
> -	 * cases and hence should use the new API drm_writeback_connector_init_with_encoder
> -	 * to initialize the writeback connector
> -	 */
> -	rc = drm_writeback_connector_init_with_encoder(dev, &dpu_wb_conn->base, enc,
> -			&dpu_wb_conn_funcs, format_list, num_formats);
> +	rc = drmm_writeback_connector_init(dev, &dpu_wb_conn->base,
> +					   &dpu_wb_conn_funcs, enc,
> +					   format_list, num_formats);
>   
>   	if (!rc)
>   		dpu_wb_conn->wb_enc = enc;
>