[PATCH 03/24] drm/msm: create the display connectors from common code
From: Dmitry Baryshkov
Date: Wed Jul 22 2026 - 02:37:01 EST
Each KMS backend (mdp4, mdp5, dpu1) open-codes the loop over the DSI, DP
and HDMI sub-blocks and the calls to msm_dsi_modeset_init(),
msm_dp_modeset_init() and msm_hdmi_modeset_init() that build the bridges
and connectors. The dispatch, including the bonded-DSI handling, is
duplicated three times with subtle variations.
The encoder each sub-block is attached to is genuinely backend-specific
(the DPU builds a display-info descriptor, MDP5 requests a CTL, MDP4 uses
fixed CRTC masks), but the connector setup that follows is not. Have each
backend only create the encoder and record it in struct msm_kms, and move
the msm_*_modeset_init() dispatch into a common msm_kms_init_connectors()
called from msm_drm_kms_init() after the backend's ->hw_init(), where the
encoders and, on DPU, the GEM address space (kms->vm) that
msm_dsi_host_modeset_init() allocates the DSI TX buffer from are set up.
No functional change intended.
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 34 ++++--------------
drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c | 18 +++-------
drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 9 +++--
drivers/gpu/drm/msm/msm_kms.c | 60 ++++++++++++++++++++++++++++++++
drivers/gpu/drm/msm/msm_kms.h | 3 ++
5 files changed, 78 insertions(+), 46 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index ede935a426d1..42dff1a98292 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -627,21 +627,11 @@ static int _dpu_kms_initialize_dsi(struct drm_device *dev,
return PTR_ERR(encoder);
}
- rc = msm_dsi_modeset_init(priv->kms->dsi[i], dev, encoder);
- if (rc) {
- DPU_ERROR("modeset_init failed for dsi[%d], rc = %d\n",
- i, rc);
- break;
- }
-
- if (msm_dsi_is_bonded_dsi(priv->kms->dsi[i]) && priv->kms->dsi[other]) {
- rc = msm_dsi_modeset_init(priv->kms->dsi[other], dev, encoder);
- if (rc) {
- DPU_ERROR("modeset_init failed for dsi[%d], rc = %d\n",
- other, rc);
- break;
- }
- }
+ /*
+ * A bonded pair is driven by a single encoder; the connector
+ * setup for both hosts is handled from common code later.
+ */
+ priv->kms->dsi_encoder[i] = encoder;
}
return rc;
@@ -653,7 +643,6 @@ static int _dpu_kms_initialize_displayport(struct drm_device *dev,
{
struct drm_encoder *encoder = NULL;
struct msm_display_info info;
- int rc;
int i;
for (i = 0; i < ARRAY_SIZE(priv->kms->dp); i++) {
@@ -671,11 +660,7 @@ static int _dpu_kms_initialize_displayport(struct drm_device *dev,
return PTR_ERR(encoder);
}
- rc = msm_dp_modeset_init(priv->kms->dp[i], dev, encoder);
- if (rc) {
- DPU_ERROR("modeset_init failed for DP, rc = %d\n", rc);
- return rc;
- }
+ priv->kms->dp_encoder[i] = encoder;
}
return 0;
@@ -687,7 +672,6 @@ static int _dpu_kms_initialize_hdmi(struct drm_device *dev,
{
struct drm_encoder *encoder = NULL;
struct msm_display_info info;
- int rc;
if (!priv->kms->hdmi)
return 0;
@@ -703,11 +687,7 @@ static int _dpu_kms_initialize_hdmi(struct drm_device *dev,
return PTR_ERR(encoder);
}
- rc = msm_hdmi_modeset_init(priv->kms->hdmi, dev, encoder);
- if (rc) {
- DPU_ERROR("modeset_init failed for DP, rc = %d\n", rc);
- return rc;
- }
+ priv->kms->hdmi_encoder = encoder;
return 0;
}
diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
index 7726edb0d4ed..cd566a287f6f 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
@@ -243,14 +243,9 @@ static int mdp4_modeset_init_intf(struct mdp4_kms *mdp4_kms,
/* DTV can be hooked to DMA_E: */
encoder->possible_crtcs = 1 << 1;
- if (priv->kms->hdmi) {
- /* Construct bridge/connector for HDMI: */
- ret = msm_hdmi_modeset_init(priv->kms->hdmi, dev, encoder);
- if (ret) {
- DRM_DEV_ERROR(dev->dev, "failed to initialize HDMI: %d\n", ret);
- return ret;
- }
- }
+ /* the bridge/connector for HDMI is set up from common code */
+ if (priv->kms->hdmi)
+ priv->kms->hdmi_encoder = encoder;
break;
case DRM_MODE_ENCODER_DSI:
@@ -271,12 +266,7 @@ static int mdp4_modeset_init_intf(struct mdp4_kms *mdp4_kms,
/* TODO: Add DMA_S later? */
encoder->possible_crtcs = 1 << DMA_P;
- ret = msm_dsi_modeset_init(priv->kms->dsi[dsi_id], dev, encoder);
- if (ret) {
- DRM_DEV_ERROR(dev->dev, "failed to initialize DSI: %d\n",
- ret);
- return ret;
- }
+ priv->kms->dsi_encoder[dsi_id] = encoder;
break;
default:
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
index 0a004ab9fc85..68b71a7c6666 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
@@ -330,7 +330,7 @@ static int modeset_init_intf(struct mdp5_kms *mdp5_kms,
break;
}
- ret = msm_hdmi_modeset_init(priv->kms->hdmi, dev, encoder);
+ priv->kms->hdmi_encoder = encoder;
break;
case INTF_DSI:
{
@@ -360,10 +360,9 @@ static int modeset_init_intf(struct mdp5_kms *mdp5_kms,
break;
}
- ret = msm_dsi_modeset_init(priv->kms->dsi[dsi_id], dev, encoder);
- if (!ret)
- mdp5_encoder_set_intf_mode(encoder,
- msm_dsi_is_cmd_mode(priv->kms->dsi[dsi_id]));
+ priv->kms->dsi_encoder[dsi_id] = encoder;
+ mdp5_encoder_set_intf_mode(encoder,
+ msm_dsi_is_cmd_mode(priv->kms->dsi[dsi_id]));
break;
}
diff --git a/drivers/gpu/drm/msm/msm_kms.c b/drivers/gpu/drm/msm/msm_kms.c
index e5d0ea629448..87530145e82b 100644
--- a/drivers/gpu/drm/msm/msm_kms.c
+++ b/drivers/gpu/drm/msm/msm_kms.c
@@ -260,6 +260,57 @@ void msm_drm_kms_uninit(struct device *dev)
kms->funcs->destroy(kms);
}
+/*
+ * Set up the bridges and connectors for the display sub-blocks, using the
+ * encoders the backend created in ->kms_init().
+ */
+static int msm_kms_init_connectors(struct drm_device *ddev)
+{
+ struct msm_drm_private *priv = ddev->dev_private;
+ struct msm_kms *kms = priv->kms;
+ int i, ret;
+
+ /*
+ * The slave link of a bonded DSI pair shares its master's encoder and
+ * creates no connector of its own; msm_dsi_modeset_init() handles that
+ * internally, so it needs no special-casing here.
+ */
+ for (i = 0; i < ARRAY_SIZE(kms->dsi); i++) {
+ if (!kms->dsi[i])
+ continue;
+
+ ret = msm_dsi_modeset_init(kms->dsi[i], ddev, kms->dsi_encoder[i]);
+ if (ret) {
+ DRM_DEV_ERROR(ddev->dev,
+ "modeset_init failed for dsi[%d]: %d\n", i, ret);
+ return ret;
+ }
+ }
+
+ for (i = 0; i < ARRAY_SIZE(kms->dp); i++) {
+ if (!kms->dp[i])
+ continue;
+
+ ret = msm_dp_modeset_init(kms->dp[i], ddev, kms->dp_encoder[i]);
+ if (ret) {
+ DRM_DEV_ERROR(ddev->dev,
+ "modeset_init failed for dp[%d]: %d\n", i, ret);
+ return ret;
+ }
+ }
+
+ if (kms->hdmi) {
+ ret = msm_hdmi_modeset_init(kms->hdmi, ddev, kms->hdmi_encoder);
+ if (ret) {
+ DRM_DEV_ERROR(ddev->dev,
+ "modeset_init failed for HDMI: %d\n", ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
int msm_drm_kms_init(struct device *dev, const struct drm_driver *drv)
{
struct msm_drm_private *priv = dev_get_drvdata(dev);
@@ -298,6 +349,15 @@ int msm_drm_kms_init(struct device *dev, const struct drm_driver *drv)
goto err_msm_uninit;
}
+ /*
+ * The backend created the encoders for each display sub-block in
+ * ->hw_init(); now set up the bridges and connectors for them from
+ * common code.
+ */
+ ret = msm_kms_init_connectors(ddev);
+ if (ret)
+ goto err_msm_uninit;
+
drm_helper_move_panel_connectors_to_head(ddev);
drm_for_each_crtc(crtc, ddev) {
diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
index f25b31e502d2..06646091604a 100644
--- a/drivers/gpu/drm/msm/msm_kms.h
+++ b/drivers/gpu/drm/msm/msm_kms.h
@@ -140,10 +140,13 @@ struct msm_kms {
struct drm_device *dev;
struct hdmi *hdmi;
+ struct drm_encoder *hdmi_encoder;
struct msm_dsi *dsi[MSM_DSI_CONTROLLER_COUNT];
+ struct drm_encoder *dsi_encoder[MSM_DSI_CONTROLLER_COUNT];
struct msm_dp *dp[MSM_DP_CONTROLLER_COUNT];
+ struct drm_encoder *dp_encoder[MSM_DP_CONTROLLER_COUNT];
/* irq number to be passed on to msm_irq_install */
int irq;
--
2.47.3