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To allows > emulating this, add two configfs attributes to connector to allows this. > > Using the dynamic attribute you can set if a connector will be dynamic or > not. > Using the enabled attribute, you can set at runtime if a dynamic connector > is present or not. > > Co-developed-by: José Expósito > Signed-off-by: José Expósito > Signed-off-by: Louis Chauvet > --- > Documentation/gpu/vkms.rst | 6 +- > drivers/gpu/drm/vkms/vkms_configfs.c | 146 ++++++++++++++++++++++++++++++++--- > 2 files changed, 139 insertions(+), 13 deletions(-) > > diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst > index bbd03f61e61c..8b17aaa28eeb 100644 > --- a/Documentation/gpu/vkms.rst > +++ b/Documentation/gpu/vkms.rst > @@ -135,7 +135,7 @@ Last but not least, create one or more connectors:: > > sudo mkdir /config/vkms/my-vkms/connectors/connector0 > > -Connectors have 5 configurable attribute: > +Connectors have 7 configurable attribute: > > - status: Connection status: 1 connected, 2 disconnected, 3 unknown (same values > as those exposed by the "status" property of a connector) > @@ -147,7 +147,9 @@ Connectors have 5 configurable attribute: > - edid_enabled: Enable or not EDID for this connector. Some connectors may not have an > EDID but just a list of modes, this attribute allows to disable EDID property. > - edid: Content of the EDID. Ignored if edid_enabled is not set > - > +- dynamic: Set to 1 while configuring the device to create a dynamic connector. A dynamic > + connector can be used to emulate DP MST connectors. > +- enabled: For dynamic connector, set it to 1 to create the connector, 0 to remove it. > > To finish the configuration, link the different pipeline items:: > > diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c > index a977c0842cd6..937b749142ad 100644 > --- a/drivers/gpu/drm/vkms/vkms_configfs.c > +++ b/drivers/gpu/drm/vkms/vkms_configfs.c > @@ -1115,8 +1115,12 @@ static ssize_t connector_status_store(struct config_item *item, > scoped_guard(mutex, &connector->dev->lock) { > vkms_config_connector_set_status(connector->config, status); > > - if (connector->dev->enabled) > - vkms_trigger_connector_hotplug(connector->dev->config->dev); > + if (connector->dev->enabled) { > + if (connector->config->dynamic && connector->config->enabled) > + vkms_trigger_connector_hotplug(connector->dev->config->dev); > + if (!connector->config->dynamic) > + vkms_trigger_connector_hotplug(connector->dev->config->dev); To avoid duplicating code, we could do something like: bool hotplug = !connector->config->dynamic || (connector->config->dynamic && connector->config->enabled); if (hotplug) vkms_trigger_connector_hotplug(connector->dev->config->dev); > + } > } > > return (ssize_t)count; > @@ -1176,8 +1180,12 @@ static ssize_t connector_type_store(struct config_item *item, > } > > scoped_guard(mutex, &connector->dev->lock) { > - if (connector->dev->enabled) > - return -EINVAL; > + if (connector->dev->enabled) { > + if (connector->config->dynamic && connector->config->enabled) > + return -EBUSY; > + if (!connector->config->dynamic) > + return -EBUSY; > + } And something similar here. Also, instead of returning -EINVAL in "drm/vkms: Introduce configfs for connector type", you could return -EBUSY and avoid changing the return type here. > vkms_config_connector_set_type(connector->config, val); > } > > @@ -1293,6 +1301,102 @@ static ssize_t connector_edid_store(struct config_item *item, > connector_status_disconnected) > vkms_trigger_connector_hotplug(connector->dev->config->dev); > } > + return count; > +} > + > +static ssize_t connector_enabled_show(struct config_item *item, char *page) > +{ > + struct vkms_configfs_connector *connector; > + bool enabled; > + > + connector = connector_item_to_vkms_configfs_connector(item); > + > + scoped_guard(mutex, &connector->dev->lock) > + enabled = vkms_config_connector_is_enabled(connector->config); > + > + return sprintf(page, "%d\n", enabled); > +} > + > +static ssize_t connector_enabled_store(struct config_item *item, > + const char *page, size_t count) > +{ > + struct vkms_configfs_connector *connector; > + struct vkms_config_connector *connector_cfg; > + bool enabled, was_enabled; > + > + connector = connector_item_to_vkms_configfs_connector(item); > + connector_cfg = connector->config; > + > + if (kstrtobool(page, &enabled)) > + return -EINVAL; > + > + if (!connector->dev->enabled) { > + vkms_config_connector_set_enabled(connector_cfg, enabled); > + } else { > + // Only dynamic connector can be enabled/disabled at runtime > + if (!connector_cfg->dynamic) > + return -EBUSY; > + > + was_enabled = vkms_config_connector_is_enabled(connector_cfg); > + vkms_config_connector_set_enabled(connector_cfg, enabled); > + > + // Resulting configuration is invalid (missing encoder for example) > + // Early return to avoid drm core issue > + if (!vkms_config_is_valid(connector->dev->config)) { > + vkms_config_connector_set_enabled(connector_cfg, was_enabled); > + return -EINVAL; > + } > + > + if (!was_enabled && enabled) { > + // Adding the connector > + connector_cfg->connector = vkms_connector_hot_add(connector->dev->config->dev, > + connector_cfg); > + if (IS_ERR(connector_cfg->connector)) { > + vkms_config_connector_set_enabled(connector_cfg, was_enabled); > + return PTR_ERR(connector_cfg->connector); > + } > + } else if (was_enabled && !enabled) { > + vkms_connector_hot_remove(connector->dev->config->dev, > + connector_cfg->connector); > + } > + } > + return count; As a suggestion, we could add a "goto rollback;" and avoid duplicating error handling: rollback: vkms_config_connector_set_enabled(connector_cfg, was_enabled); return ret; > +} > + > +static ssize_t connector_dynamic_show(struct config_item *item, char *page) > +{ > + struct vkms_configfs_connector *connector; > + bool enabled; > + > + connector = connector_item_to_vkms_configfs_connector(item); > + > + scoped_guard(mutex, &connector->dev->lock) { > + enabled = vkms_config_connector_is_dynamic(connector->config); > + } > + > + return sprintf(page, "%d\n", enabled); > +} > + > +static ssize_t connector_dynamic_store(struct config_item *item, > + const char *page, size_t count) > +{ > + struct vkms_configfs_connector *connector; > + struct vkms_config_connector *connector_cfg; > + bool dynamic; > + > + connector = connector_item_to_vkms_configfs_connector(item); > + connector_cfg = connector->config; > + > + if (kstrtobool(page, &dynamic)) > + return -EINVAL; > + > + scoped_guard(mutex, &connector->dev->lock) { > + // Can't change the dynamic status when the device is activated > + if (connector->dev->enabled) > + return -EBUSY; > + > + vkms_config_connector_set_dynamic(connector_cfg, dynamic); > + } > > return count; > } > @@ -1302,6 +1406,8 @@ CONFIGFS_ATTR(connector_, type); > CONFIGFS_ATTR(connector_, supported_colorspaces); > CONFIGFS_ATTR(connector_, edid_enabled); > CONFIGFS_ATTR(connector_, edid); > +CONFIGFS_ATTR(connector_, dynamic); > +CONFIGFS_ATTR(connector_, enabled); > > static struct configfs_attribute *connector_item_attrs[] = { > &connector_attr_status, > @@ -1309,19 +1415,28 @@ static struct configfs_attribute *connector_item_attrs[] = { > &connector_attr_supported_colorspaces, > &connector_attr_edid_enabled, > &connector_attr_edid, > + &connector_attr_dynamic, > + &connector_attr_enabled, > NULL, > }; > > static void connector_release(struct config_item *item) > { > struct vkms_configfs_connector *connector; > + struct vkms_config_connector *connector_cfg; > struct mutex *lock; > > connector = connector_item_to_vkms_configfs_connector(item); > + connector_cfg = connector->config; > lock = &connector->dev->lock; > > scoped_guard(mutex, lock) { > + if (connector->dev->enabled && connector_cfg->dynamic && connector_cfg->enabled) > + vkms_connector_hot_remove(connector->dev->config->dev, > + connector_cfg->connector); > + > vkms_config_destroy_connector(connector->config); > + > kfree(connector); > } > } > @@ -1340,6 +1455,7 @@ static int connector_possible_encoders_allow_link(struct config_item *src, > struct config_item *target) > { > struct vkms_configfs_connector *connector; > + struct vkms_config_connector *connector_cfg; > struct vkms_configfs_encoder *encoder; > int ret; > > @@ -1347,16 +1463,25 @@ static int connector_possible_encoders_allow_link(struct config_item *src, > return -EINVAL; > > connector = connector_possible_encoders_item_to_vkms_configfs_connector(src); > + connector_cfg = connector->config; > encoder = encoder_item_to_vkms_configfs_encoder(target); > > scoped_guard(mutex, &connector->dev->lock) { > - if (connector->dev->enabled) > - return -EBUSY; > + if (connector->dev->enabled && connector_cfg->enabled) { > + if (!connector_cfg->dynamic) > + return -EBUSY; > + ret = vkms_connector_hot_attach_encoder(connector->dev->config->dev, > + connector->config->connector, > + encoder->config->encoder); > + if (ret) > + return ret; > + } > > ret = vkms_config_connector_attach_encoder(connector->config, > encoder->config); > + if (ret) > + return ret; > } > - > return ret; > } > > @@ -1394,9 +1519,6 @@ static struct config_group *make_connector_group(struct config_group *group, > dev = child_group_to_vkms_configfs_device(group); > > scoped_guard(mutex, &dev->lock) { > - if (dev->enabled) > - return ERR_PTR(-EBUSY); > - > connector = kzalloc(sizeof(*connector), GFP_KERNEL); > if (!connector) > return ERR_PTR(-ENOMEM); > @@ -1409,9 +1531,11 @@ static struct config_group *make_connector_group(struct config_group *group, > return ERR_CAST(connector->config); > } > > + vkms_config_connector_set_dynamic(connector->config, connector->dev->enabled); > + vkms_config_connector_set_enabled(connector->config, !connector->dev->enabled); > + > config_group_init_type_name(&connector->group, name, > &connector_item_type); > - > config_group_init_type_name(&connector->possible_encoders_group, > "possible_encoders", > &connector_possible_encoders_group_type); > > -- > 2.51.0 >