diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index afec53832145968feb5cfa24e38ead1675dbfcac..3b6e6e924e3c6df38d84d47d6706a267161dfc3a 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -1109,6 +1109,20 @@ int drm_atomic_connector_set_property(struct drm_connector *connector, state->tv.saturation = val; } else if (property == config->tv_hue_property) { state->tv.hue = val; + } else if (property == config->link_status_property) { + /* Never downgrade from GOOD to BAD on userspace's request here, + * only hw issues can do that. + * + * For an atomic property the userspace doesn't need to be able + * to understand all the properties, but needs to be able to + * restore the state it wants on VT switch. So if the userspace + * tries to change the link_status from GOOD to BAD, driver + * silently rejects it and returns a 0. This prevents userspace + * from accidently breaking the display when it restores the + * state. + */ + if (state->link_status != DRM_LINK_STATUS_GOOD) + state->link_status = val; } else if (connector->funcs->atomic_set_property) { return connector->funcs->atomic_set_property(connector, state, property, val); @@ -1183,6 +1197,8 @@ drm_atomic_connector_get_property(struct drm_connector *connector, *val = state->tv.saturation; } else if (property == config->tv_hue_property) { *val = state->tv.hue; + } else if (property == config->link_status_property) { + *val = state->link_status; } else if (connector->funcs->atomic_get_property) { return connector->funcs->atomic_get_property(connector, state, property, val); diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 9203f3e933f7a35fa6ba6f1c22be7b8089878fa5..2e62b332ae8bc57d661ab60276f4b5323a11d145 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -530,6 +530,13 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, connector_state); if (ret) return ret; + if (connector->state->crtc) { + crtc_state = drm_atomic_get_existing_crtc_state(state, + connector->state->crtc); + if (connector->state->link_status != + connector_state->link_status) + crtc_state->connectors_changed = true; + } } /* @@ -2241,6 +2248,8 @@ static int update_output_state(struct drm_atomic_state *state, NULL); if (ret) return ret; + /* Make sure legacy setCrtc always re-trains */ + conn_state->link_status = DRM_LINK_STATUS_GOOD; } } @@ -2284,6 +2293,12 @@ static int update_output_state(struct drm_atomic_state *state, * * Provides a default crtc set_config handler using the atomic driver interface. * + * NOTE: For backwards compatibility with old userspace this automatically + * resets the "link-status" property to GOOD, to force any link + * re-training. The SETCRTC ioctl does not define whether an update does + * need a full modeset or just a plane update, hence we're allowed to do + * that. See also drm_mode_connector_set_link_status_property(). + * * Returns: * Returns 0 on success, negative errno numbers on failure. */ diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c index 45464c8b797dea1edca2efd29590a970cd45514e..ab73e86ffdf1b250b150a92c3f7d21d5c0f3fef4 100644 --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -244,6 +244,10 @@ int drm_connector_init(struct drm_device *dev, drm_object_attach_property(&connector->base, config->dpms_property, 0); + drm_object_attach_property(&connector->base, + config->link_status_property, + 0); + if (drm_core_check_feature(dev, DRIVER_ATOMIC)) { drm_object_attach_property(&connector->base, config->prop_crtc_id, 0); } @@ -599,6 +603,12 @@ static const struct drm_prop_enum_list drm_dpms_enum_list[] = { }; DRM_ENUM_NAME_FN(drm_get_dpms_name, drm_dpms_enum_list) +static const struct drm_prop_enum_list drm_link_status_enum_list[] = { + { DRM_MODE_LINK_STATUS_GOOD, "Good" }, + { DRM_MODE_LINK_STATUS_BAD, "Bad" }, +}; +DRM_ENUM_NAME_FN(drm_get_link_status_name, drm_link_status_enum_list) + /** * drm_display_info_set_bus_formats - set the supported bus formats * @info: display info to store bus formats in @@ -718,6 +728,11 @@ DRM_ENUM_NAME_FN(drm_get_tv_subconnector_name, * tiling and virtualize both &drm_crtc and &drm_plane if needed. Drivers * should update this value using drm_mode_connector_set_tile_property(). * Userspace cannot change this property. + * link-status: + * Connector link-status property to indicate the status of link. The default + * value of link-status is "GOOD". If something fails during or after modeset, + * the kernel driver may set this to "BAD" and issue a hotplug uevent. Drivers + * should update this value using drm_mode_connector_set_link_status_property(). * * Connectors also have one standardized atomic property: * @@ -759,6 +774,13 @@ int drm_connector_create_standard_properties(struct drm_device *dev) return -ENOMEM; dev->mode_config.tile_property = prop; + prop = drm_property_create_enum(dev, 0, "link-status", + drm_link_status_enum_list, + ARRAY_SIZE(drm_link_status_enum_list)); + if (!prop) + return -ENOMEM; + dev->mode_config.link_status_property = prop; + return 0; } @@ -1088,6 +1110,36 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector, } EXPORT_SYMBOL(drm_mode_connector_update_edid_property); +/** + * drm_mode_connector_set_link_status_property - Set link status property of a connector + * @connector: drm connector + * @link_status: new value of link status property (0: Good, 1: Bad) + * + * In usual working scenario, this link status property will always be set to + * "GOOD". If something fails during or after a mode set, the kernel driver + * may set this link status property to "BAD". The caller then needs to send a + * hotplug uevent for userspace to re-check the valid modes through + * GET_CONNECTOR_IOCTL and retry modeset. + * + * Note: Drivers cannot rely on userspace to support this property and + * issue a modeset. As such, they may choose to handle issues (like + * re-training a link) without userspace's intervention. + * + * The reason for adding this property is to handle link training failures, but + * it is not limited to DP or link training. For example, if we implement + * asynchronous setcrtc, this property can be used to report any failures in that. + */ +void drm_mode_connector_set_link_status_property(struct drm_connector *connector, + uint64_t link_status) +{ + struct drm_device *dev = connector->dev; + + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); + connector->state->link_status = link_status; + drm_modeset_unlock(&dev->mode_config.connection_mutex); +} +EXPORT_SYMBOL(drm_mode_connector_set_link_status_property); + int drm_mode_connector_set_obj_prop(struct drm_mode_object *obj, struct drm_property *property, uint64_t value) diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index e5e1eddd19fb19d168a18fb2607c0a5c81e2ec37..f08aa5dfc9d78c9e45eadb1f276b14e7e59f2e20 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -89,6 +89,17 @@ enum subpixel_order { SubPixelNone, }; +/** + * enum drm_link_status - connector's link_status property value + * + * This enum is used as the connector's link status property value. + * It is set to the values defined in uapi. + */ +enum drm_link_status { + DRM_LINK_STATUS_GOOD = DRM_MODE_LINK_STATUS_GOOD, + DRM_LINK_STATUS_BAD = DRM_MODE_LINK_STATUS_BAD, +}; + /** * struct drm_display_info - runtime data about the connected sink * @@ -243,6 +254,12 @@ struct drm_connector_state { struct drm_encoder *best_encoder; + /** + * @link_status: Connector link_status to keep track of whether link is + * GOOD or BAD to notify userspace if retraining is necessary. + */ + enum drm_link_status link_status; + struct drm_atomic_state *state; struct drm_tv_connector_state tv; @@ -837,6 +854,8 @@ int drm_mode_connector_set_path_property(struct drm_connector *connector, int drm_mode_connector_set_tile_property(struct drm_connector *connector); int drm_mode_connector_update_edid_property(struct drm_connector *connector, const struct edid *edid); +void drm_mode_connector_set_link_status_property(struct drm_connector *connector, + uint64_t link_status); /** * struct drm_tile_group - Tile group metadata diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h index f220ee909bdb909f7aaf99cb3fd1f68b16961e2c..ea169a90b3c4322d010b7dccb260be22eff791a5 100644 --- a/include/drm/drm_mode_config.h +++ b/include/drm/drm_mode_config.h @@ -438,6 +438,11 @@ struct drm_mode_config { * multiple CRTCs. */ struct drm_property *tile_property; + /** + * @link_status_property: Default connector property for link status + * of a connector + */ + struct drm_property *link_status_property; /** * @plane_type_property: Default plane property to differentiate * CURSOR, PRIMARY and OVERLAY legacy uses of planes. diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index ce7efe2e8a5e7698308b879b7d4c9826614b4673..8c67fc03d53dd630a8245fd2ae79fae5d5cbaccc 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -123,6 +123,10 @@ extern "C" { #define DRM_MODE_DIRTY_ON 1 #define DRM_MODE_DIRTY_ANNOTATE 2 +/* Link Status options */ +#define DRM_MODE_LINK_STATUS_GOOD 0 +#define DRM_MODE_LINK_STATUS_BAD 1 + struct drm_mode_modeinfo { __u32 clock; __u16 hdisplay;