From 2be300f9a0b6f6b0ae2a90be97e558ec0535be54 Mon Sep 17 00:00:00 2001 From: Luca Ceresoli Date: Fri, 26 Sep 2025 16:59:40 +0200 Subject: [PATCH] drm/display: bridge_connector: get/put the stored bridges drm_bridge_connector_init() takes eight pointers to various bridges, some of which can be identical, and stores them in pointers inside struct drm_bridge_connector. Get a reference to each of the taken bridges and put it on cleanup. This is tricky because the pointers are currently stored directly in the drm_bridge_connector in the loop, but there is no nice and clean way to put those pointers on error return paths. To overcome this, store all pointers in temporary local variables with a cleanup action, and only on success copy them into struct drm_bridge_connector (getting another ref while copying). Additionally four of these pointers (edid, hpd, detect and modes) can be written in multiple loop iterations, in order to eventually store the last matching bridge. However, when one of those pointers is overwritten, we need to put the reference that we got during the previous assignment. Add a drm_bridge_put() before writing them to handle this. Finally, there is also a function-local panel_bridge pointer taken inside the loop and used after the loop. Use a cleanup action as well to ensure it is put on return. Reviewed-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20250926-drm-bridge-alloc-getput-bridge-connector-v2-1-138b4bb70576@bootlin.com Signed-off-by: Luca Ceresoli --- .../gpu/drm/display/drm_bridge_connector.c | 114 ++++++++++++------ 1 file changed, 78 insertions(+), 36 deletions(-) diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c index a5bdd6c106439..7b18be3ff9a32 100644 --- a/drivers/gpu/drm/display/drm_bridge_connector.c +++ b/drivers/gpu/drm/display/drm_bridge_connector.c @@ -618,6 +618,20 @@ static const struct drm_connector_hdmi_cec_funcs drm_bridge_connector_hdmi_cec_f * Bridge Connector Initialisation */ +static void drm_bridge_connector_put_bridges(struct drm_device *dev, void *data) +{ + struct drm_bridge_connector *bridge_connector = (struct drm_bridge_connector *)data; + + drm_bridge_put(bridge_connector->bridge_edid); + drm_bridge_put(bridge_connector->bridge_hpd); + drm_bridge_put(bridge_connector->bridge_detect); + drm_bridge_put(bridge_connector->bridge_modes); + drm_bridge_put(bridge_connector->bridge_hdmi); + drm_bridge_put(bridge_connector->bridge_hdmi_audio); + drm_bridge_put(bridge_connector->bridge_dp_audio); + drm_bridge_put(bridge_connector->bridge_hdmi_cec); +} + /** * drm_bridge_connector_init - Initialise a connector for a chain of bridges * @drm: the DRM device @@ -638,7 +652,15 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, struct drm_bridge_connector *bridge_connector; struct drm_connector *connector; struct i2c_adapter *ddc = NULL; - struct drm_bridge *panel_bridge = NULL; + struct drm_bridge *panel_bridge __free(drm_bridge_put) = NULL; + struct drm_bridge *bridge_edid __free(drm_bridge_put) = NULL; + struct drm_bridge *bridge_hpd __free(drm_bridge_put) = NULL; + struct drm_bridge *bridge_detect __free(drm_bridge_put) = NULL; + struct drm_bridge *bridge_modes __free(drm_bridge_put) = NULL; + struct drm_bridge *bridge_hdmi __free(drm_bridge_put) = NULL; + struct drm_bridge *bridge_hdmi_audio __free(drm_bridge_put) = NULL; + struct drm_bridge *bridge_dp_audio __free(drm_bridge_put) = NULL; + struct drm_bridge *bridge_hdmi_cec __free(drm_bridge_put) = NULL; unsigned int supported_formats = BIT(HDMI_COLORSPACE_RGB); unsigned int max_bpc = 8; bool support_hdcp = false; @@ -649,6 +671,10 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, if (!bridge_connector) return ERR_PTR(-ENOMEM); + ret = drmm_add_action(drm, drm_bridge_connector_put_bridges, bridge_connector); + if (ret) + return ERR_PTR(ret); + bridge_connector->encoder = encoder; /* @@ -672,22 +698,30 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, if (!bridge->ycbcr_420_allowed) connector->ycbcr_420_allowed = false; - if (bridge->ops & DRM_BRIDGE_OP_EDID) - bridge_connector->bridge_edid = bridge; - if (bridge->ops & DRM_BRIDGE_OP_HPD) - bridge_connector->bridge_hpd = bridge; - if (bridge->ops & DRM_BRIDGE_OP_DETECT) - bridge_connector->bridge_detect = bridge; - if (bridge->ops & DRM_BRIDGE_OP_MODES) - bridge_connector->bridge_modes = bridge; + if (bridge->ops & DRM_BRIDGE_OP_EDID) { + drm_bridge_put(bridge_edid); + bridge_edid = drm_bridge_get(bridge); + } + if (bridge->ops & DRM_BRIDGE_OP_HPD) { + drm_bridge_put(bridge_hpd); + bridge_hpd = drm_bridge_get(bridge); + } + if (bridge->ops & DRM_BRIDGE_OP_DETECT) { + drm_bridge_put(bridge_detect); + bridge_detect = drm_bridge_get(bridge); + } + if (bridge->ops & DRM_BRIDGE_OP_MODES) { + drm_bridge_put(bridge_modes); + bridge_modes = drm_bridge_get(bridge); + } if (bridge->ops & DRM_BRIDGE_OP_HDMI) { - if (bridge_connector->bridge_hdmi) + if (bridge_hdmi) return ERR_PTR(-EBUSY); if (!bridge->funcs->hdmi_write_infoframe || !bridge->funcs->hdmi_clear_infoframe) return ERR_PTR(-EINVAL); - bridge_connector->bridge_hdmi = bridge; + bridge_hdmi = drm_bridge_get(bridge); if (bridge->supported_formats) supported_formats = bridge->supported_formats; @@ -696,10 +730,10 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, } if (bridge->ops & DRM_BRIDGE_OP_HDMI_AUDIO) { - if (bridge_connector->bridge_hdmi_audio) + if (bridge_hdmi_audio) return ERR_PTR(-EBUSY); - if (bridge_connector->bridge_dp_audio) + if (bridge_dp_audio) return ERR_PTR(-EBUSY); if (!bridge->hdmi_audio_max_i2s_playback_channels && @@ -710,14 +744,14 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, !bridge->funcs->hdmi_audio_shutdown) return ERR_PTR(-EINVAL); - bridge_connector->bridge_hdmi_audio = bridge; + bridge_hdmi_audio = drm_bridge_get(bridge); } if (bridge->ops & DRM_BRIDGE_OP_DP_AUDIO) { - if (bridge_connector->bridge_dp_audio) + if (bridge_dp_audio) return ERR_PTR(-EBUSY); - if (bridge_connector->bridge_hdmi_audio) + if (bridge_hdmi_audio) return ERR_PTR(-EBUSY); if (!bridge->hdmi_audio_max_i2s_playback_channels && @@ -728,7 +762,7 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, !bridge->funcs->dp_audio_shutdown) return ERR_PTR(-EINVAL); - bridge_connector->bridge_dp_audio = bridge; + bridge_dp_audio = drm_bridge_get(bridge); } if (bridge->ops & DRM_BRIDGE_OP_HDMI_CEC_NOTIFIER) { @@ -739,10 +773,10 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, } if (bridge->ops & DRM_BRIDGE_OP_HDMI_CEC_ADAPTER) { - if (bridge_connector->bridge_hdmi_cec) + if (bridge_hdmi_cec) return ERR_PTR(-EBUSY); - bridge_connector->bridge_hdmi_cec = bridge; + bridge_hdmi_cec = drm_bridge_get(bridge); if (!bridge->funcs->hdmi_cec_enable || !bridge->funcs->hdmi_cec_log_addr || @@ -762,7 +796,7 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, ddc = bridge->ddc; if (drm_bridge_is_panel(bridge)) - panel_bridge = bridge; + panel_bridge = drm_bridge_get(bridge); if (bridge->support_hdcp) support_hdcp = true; @@ -771,13 +805,13 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, if (connector_type == DRM_MODE_CONNECTOR_Unknown) return ERR_PTR(-EINVAL); - if (bridge_connector->bridge_hdmi) { + if (bridge_hdmi) { if (!connector->ycbcr_420_allowed) supported_formats &= ~BIT(HDMI_COLORSPACE_YUV420); ret = drmm_connector_hdmi_init(drm, connector, - bridge_connector->bridge_hdmi->vendor, - bridge_connector->bridge_hdmi->product, + bridge_hdmi->vendor, + bridge_hdmi->product, &drm_bridge_connector_funcs, &drm_bridge_connector_hdmi_funcs, connector_type, ddc, @@ -793,15 +827,14 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, return ERR_PTR(ret); } - if (bridge_connector->bridge_hdmi_audio || - bridge_connector->bridge_dp_audio) { + if (bridge_hdmi_audio || bridge_dp_audio) { struct device *dev; struct drm_bridge *bridge; - if (bridge_connector->bridge_hdmi_audio) - bridge = bridge_connector->bridge_hdmi_audio; + if (bridge_hdmi_audio) + bridge = bridge_hdmi_audio; else - bridge = bridge_connector->bridge_dp_audio; + bridge = bridge_dp_audio; dev = bridge->hdmi_audio_dev; @@ -815,9 +848,9 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, return ERR_PTR(ret); } - if (bridge_connector->bridge_hdmi_cec && - bridge_connector->bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_NOTIFIER) { - struct drm_bridge *bridge = bridge_connector->bridge_hdmi_cec; + if (bridge_hdmi_cec && + bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_NOTIFIER) { + struct drm_bridge *bridge = bridge_hdmi_cec; ret = drmm_connector_hdmi_cec_notifier_register(connector, NULL, @@ -826,9 +859,9 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, return ERR_PTR(ret); } - if (bridge_connector->bridge_hdmi_cec && - bridge_connector->bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_ADAPTER) { - struct drm_bridge *bridge = bridge_connector->bridge_hdmi_cec; + if (bridge_hdmi_cec && + bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_ADAPTER) { + struct drm_bridge *bridge = bridge_hdmi_cec; ret = drmm_connector_hdmi_cec_register(connector, &drm_bridge_connector_hdmi_cec_funcs, @@ -841,9 +874,9 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs); - if (bridge_connector->bridge_hpd) + if (bridge_hpd) connector->polled = DRM_CONNECTOR_POLL_HPD; - else if (bridge_connector->bridge_detect) + else if (bridge_detect) connector->polled = DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT; @@ -854,6 +887,15 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm, IS_ENABLED(CONFIG_DRM_DISPLAY_HDCP_HELPER)) drm_connector_attach_content_protection_property(connector, true); + bridge_connector->bridge_edid = drm_bridge_get(bridge_edid); + bridge_connector->bridge_hpd = drm_bridge_get(bridge_hpd); + bridge_connector->bridge_detect = drm_bridge_get(bridge_detect); + bridge_connector->bridge_modes = drm_bridge_get(bridge_modes); + bridge_connector->bridge_hdmi = drm_bridge_get(bridge_hdmi); + bridge_connector->bridge_hdmi_audio = drm_bridge_get(bridge_hdmi_audio); + bridge_connector->bridge_dp_audio = drm_bridge_get(bridge_dp_audio); + bridge_connector->bridge_hdmi_cec = drm_bridge_get(bridge_hdmi_cec); + return connector; } EXPORT_SYMBOL_GPL(drm_bridge_connector_init); -- 2.47.3