From: Jayesh Choudhary Date: Tue, 9 Dec 2025 12:03:27 +0000 (+0530) Subject: drm/bridge: cadence: cdns-mhdp8546-core: Set the mhdp connector earlier in atomic_ena... X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=43d6508ddbf9fb974fbc359a033154f78c9d4c8b;p=thirdparty%2Fkernel%2Flinux.git drm/bridge: cadence: cdns-mhdp8546-core: Set the mhdp connector earlier in atomic_enable() In case if we get errors in cdns_mhdp_link_up() or cdns_mhdp_reg_read() in atomic_enable, we will go to cdns_mhdp_modeset_retry_fn() and will hit NULL pointer while trying to access the mutex. We need the connector to be set before that. Unlike in legacy cases with flag !DRM_BRIDGE_ATTACH_NO_CONNECTOR, we do not have connector initialised in bridge_attach(), so add the mhdp->connector_ptr in device structure to handle both cases with DRM_BRIDGE_ATTACH_NO_CONNECTOR and !DRM_BRIDGE_ATTACH_NO_CONNECTOR, set it in atomic_enable() earlier to avoid possible NULL pointer dereference in recovery paths like modeset_retry_fn() with the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag set. Fixes: c932ced6b585 ("drm/tidss: Update encoder/bridge chain connect model") Signed-off-by: Jayesh Choudhary Signed-off-by: Harikrishna Shenoy Reviewed-by: Luca Ceresoli Reviewed-by: Tomi Valkeinen Link: https://patch.msgid.link/20251209120332.3559893-2-h-shenoy@ti.com Signed-off-by: Luca Ceresoli --- diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c index 9392c226ff5b1..3379194e4ea6b 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c @@ -740,7 +740,7 @@ static void cdns_mhdp_fw_cb(const struct firmware *fw, void *context) bridge_attached = mhdp->bridge_attached; spin_unlock(&mhdp->start_lock); if (bridge_attached) { - if (mhdp->connector.dev) + if (mhdp->connector_ptr) drm_kms_helper_hotplug_event(mhdp->bridge.dev); else drm_bridge_hpd_notify(&mhdp->bridge, cdns_mhdp_detect(mhdp)); @@ -1636,6 +1636,7 @@ static int cdns_mhdp_connector_init(struct cdns_mhdp_device *mhdp) return ret; } + mhdp->connector_ptr = conn; drm_connector_helper_add(conn, &cdns_mhdp_conn_helper_funcs); ret = drm_display_info_set_bus_formats(&conn->display_info, @@ -1915,17 +1916,25 @@ static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge, struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge); struct cdns_mhdp_bridge_state *mhdp_state; struct drm_crtc_state *crtc_state; - struct drm_connector *connector; struct drm_connector_state *conn_state; struct drm_bridge_state *new_state; const struct drm_display_mode *mode; u32 resp; - int ret; + int ret = 0; dev_dbg(mhdp->dev, "bridge enable\n"); mutex_lock(&mhdp->link_mutex); + mhdp->connector_ptr = drm_atomic_get_new_connector_for_encoder(state, + bridge->encoder); + if (WARN_ON(!mhdp->connector_ptr)) + goto out; + + conn_state = drm_atomic_get_new_connector_state(state, mhdp->connector_ptr); + if (WARN_ON(!conn_state)) + goto out; + if (mhdp->plugged && !mhdp->link_up) { ret = cdns_mhdp_link_up(mhdp); if (ret < 0) @@ -1945,15 +1954,6 @@ static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge, cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR, resp | CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN); - connector = drm_atomic_get_new_connector_for_encoder(state, - bridge->encoder); - if (WARN_ON(!connector)) - goto out; - - conn_state = drm_atomic_get_new_connector_state(state, connector); - if (WARN_ON(!conn_state)) - goto out; - if (mhdp->hdcp_supported && mhdp->hw_state == MHDP_HW_READY && conn_state->content_protection == @@ -2030,6 +2030,7 @@ static void cdns_mhdp_atomic_disable(struct drm_bridge *bridge, if (mhdp->info && mhdp->info->ops && mhdp->info->ops->disable) mhdp->info->ops->disable(mhdp); + mhdp->connector_ptr = NULL; mutex_unlock(&mhdp->link_mutex); } @@ -2296,7 +2297,7 @@ static void cdns_mhdp_modeset_retry_fn(struct work_struct *work) mhdp = container_of(work, typeof(*mhdp), modeset_retry_work); - conn = &mhdp->connector; + conn = mhdp->connector_ptr; /* Grab the locks before changing connector property */ mutex_lock(&conn->dev->mode_config.mutex); @@ -2373,7 +2374,7 @@ static void cdns_mhdp_hpd_work(struct work_struct *work) int ret; ret = cdns_mhdp_update_link_status(mhdp); - if (mhdp->connector.dev) { + if (mhdp->connector_ptr) { if (ret < 0) schedule_work(&mhdp->modeset_retry_work); else diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h index bad2fc0c73066..a76775c768956 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h @@ -376,6 +376,7 @@ struct cdns_mhdp_device { struct mutex link_mutex; struct drm_connector connector; + struct drm_connector *connector_ptr; struct drm_bridge bridge; struct cdns_mhdp_link link; diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c index 42248f179b69d..21a7d2fb266e4 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c @@ -394,7 +394,7 @@ static int _cdns_mhdp_hdcp_disable(struct cdns_mhdp_device *mhdp) int ret; dev_dbg(mhdp->dev, "[%s:%d] HDCP is being disabled...\n", - mhdp->connector.name, mhdp->connector.base.id); + mhdp->connector_ptr->name, mhdp->connector_ptr->base.id); ret = cdns_mhdp_hdcp_set_config(mhdp, 0, false); @@ -436,6 +436,10 @@ static int cdns_mhdp_hdcp_check_link(struct cdns_mhdp_device *mhdp) int ret = 0; mutex_lock(&mhdp->hdcp.mutex); + + if (!mhdp->connector_ptr) + goto out; + if (mhdp->hdcp.value == DRM_MODE_CONTENT_PROTECTION_UNDESIRED) goto out; @@ -445,7 +449,7 @@ static int cdns_mhdp_hdcp_check_link(struct cdns_mhdp_device *mhdp) dev_err(mhdp->dev, "[%s:%d] HDCP link failed, retrying authentication\n", - mhdp->connector.name, mhdp->connector.base.id); + mhdp->connector_ptr->name, mhdp->connector_ptr->base.id); ret = _cdns_mhdp_hdcp_disable(mhdp); if (ret) { @@ -487,13 +491,19 @@ static void cdns_mhdp_hdcp_prop_work(struct work_struct *work) struct cdns_mhdp_device *mhdp = container_of(hdcp, struct cdns_mhdp_device, hdcp); - struct drm_device *dev = mhdp->connector.dev; + struct drm_device *dev = NULL; struct drm_connector_state *state; + if (mhdp->connector_ptr) + dev = mhdp->connector_ptr->dev; + + if (!dev) + return; + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); mutex_lock(&mhdp->hdcp.mutex); if (mhdp->hdcp.value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) { - state = mhdp->connector.state; + state = mhdp->connector_ptr->state; state->content_protection = mhdp->hdcp.value; } mutex_unlock(&mhdp->hdcp.mutex);