[PATCH 0/2] drm/xlnx/zynqmp_dpsub: improve usage of drm encoder

[PATCH 0/2] drm/xlnx/zynqmp_dpsub: improve usage of drm encoder

[Diogo Silva]

This series addresses two things:
 - Remove the usage of the deprecated drm_simple_encoder_init on the
   zynqmp_dpsub driver, substituting by drm_encoder_init
 - Add a return value check for the drm_encoder_init, preventing a
   potentially uninitialized encoder being cleaned up

Signed-off-by: Diogo Silva <diogompaissilva@gmail.com>
---
Diogo Silva (2):
      drm/xlnx/zynqmp_dpsub: remove dependency on DRM simple helpers
      drm/xlnx/zynqmp_dpsub: check return value on drm_encoder_init

 drivers/gpu/drm/xlnx/zynqmp_kms.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
---
base-commit: 7a8782fa5da551a92ada0aca6f7dbadfc4c36da3
change-id: 20260707-xlnx-simple-12cd05c1d745

Best regards,
-- 
Diogo Silva <diogompaissilva@gmail.com>

[PATCH 1/2] drm/xlnx/zynqmp_dpsub: remove dependency on DRM simple helpers

[Diogo Silva]

Simple KMS helper are deprecated since they only add an intermediate
layer between drivers and the atomic modesetting.
This patch removes the drm_simple_encoder_init() helper usage in the
xlnx zynqmp_dpsub driver by open coding it and using the encoder atomic
helpers directly. This is a step to eventually get rid of this simple
KMS helper, once all drivers that use it have been converted.

Signed-off-by: Diogo Silva <diogompaissilva@gmail.com>
---
 drivers/gpu/drm/xlnx/zynqmp_kms.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_kms.c b/drivers/gpu/drm/xlnx/zynqmp_kms.c
index d5f9224505655..698ac692abce9 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_kms.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_kms.c
@@ -30,7 +30,6 @@
 #include <drm/drm_mode_config.h>
 #include <drm/drm_plane.h>
 #include <drm/drm_probe_helper.h>
-#include <drm/drm_simple_kms_helper.h>
 #include <drm/drm_vblank.h>
 
 #include <linux/clk.h>
@@ -417,6 +416,10 @@ static const struct drm_driver zynqmp_dpsub_drm_driver = {
 	.minor				= 0,
 };
 
+static const struct drm_encoder_funcs zynqmp_dpsub_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
 static int zynqmp_dpsub_kms_init(struct zynqmp_dpsub *dpsub)
 {
 	struct drm_encoder *encoder = &dpsub->drm->encoder;
@@ -436,7 +439,8 @@ static int zynqmp_dpsub_kms_init(struct zynqmp_dpsub *dpsub)
 
 	/* Create the encoder and attach the bridge. */
 	encoder->possible_crtcs |= drm_crtc_mask(&dpsub->drm->crtc);
-	drm_simple_encoder_init(&dpsub->drm->dev, encoder, DRM_MODE_ENCODER_NONE);
+	drm_encoder_init(&dpsub->drm->dev, encoder, &zynqmp_dpsub_encoder_funcs,
+			 DRM_MODE_ENCODER_NONE, NULL);
 
 	ret = drm_bridge_attach(encoder, dpsub->bridge, NULL,
 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);

-- 
2.51.2

[PATCH 2/2] drm/xlnx/zynqmp_dpsub: check return value on drm_encoder_init

[Diogo Silva]

A call to drm_encoder_init() can fail. If the error code is not checked
this may lead to drm_encoder_cleanup() being called on an uninitialized
drm_encoder.
This patch addresses this by adding the proper return value check to the
drm_encoder_init() function call.

Signed-off-by: Diogo Silva <diogompaissilva@gmail.com>
---
 drivers/gpu/drm/xlnx/zynqmp_kms.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_kms.c b/drivers/gpu/drm/xlnx/zynqmp_kms.c
index 698ac692abce..1d194c2824e3 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_kms.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_kms.c
@@ -439,8 +439,13 @@ static int zynqmp_dpsub_kms_init(struct zynqmp_dpsub *dpsub)
 
 	/* Create the encoder and attach the bridge. */
 	encoder->possible_crtcs |= drm_crtc_mask(&dpsub->drm->crtc);
-	drm_encoder_init(&dpsub->drm->dev, encoder, &zynqmp_dpsub_encoder_funcs,
-			 DRM_MODE_ENCODER_NONE, NULL);
+	ret = drm_encoder_init(&dpsub->drm->dev, encoder,
+			       &zynqmp_dpsub_encoder_funcs,
+			       DRM_MODE_ENCODER_NONE, NULL);
+	if (ret) {
+		dev_err(dpsub->dev, "failed to initialize encoder\n");
+		return ret;
+	}
 
 	ret = drm_bridge_attach(encoder, dpsub->bridge, NULL,
 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);

-- 
2.51.2