On Tue, Nov 11, 2025 at 06:23:35PM +0200, Marius Vlad wrote:
> Introduce a new boolean variable used to track connector's
> connect/disconnect status and it is being used on both polling and the
> HPD (Hot Plug Detect) paths.
>
> A subsequent change would make use of this connector status to propagate
> per-connector udev hotplug events.
>
> The connector status is set in the drm_connector_funcs.fill_modes/vkms
> ConfigFS connector's status and cleared out when firing out KMS uevents.
>
> Allows user-space to receive the connector's ID, rather than having a
> generic hot-plug event for all connectors, or in the HPD path, just the
> first one found with a connection status change.
>
> Signed-off-by: Marius Vlad <[email protected]>
> ---
> drivers/gpu/drm/drm_connector.c | 1 +
> drivers/gpu/drm/drm_probe_helper.c | 17 +++++++++++++++++
> drivers/gpu/drm/drm_sysfs.c | 1 +
> drivers/gpu/drm/vkms/vkms_configfs.c | 6 ++++++
> include/drm/drm_connector.h | 3 +++
> 5 files changed, 28 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 272d6254ea47..3c6628ee3096 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -274,6 +274,7 @@ static int drm_connector_init_only(struct drm_device *dev,
>
> /* provide ddc symlink in sysfs */
> connector->ddc = ddc;
> + connector->status_changed = false;
>
> INIT_LIST_HEAD(&connector->head);
> INIT_LIST_HEAD(&connector->global_connector_list_entry);
> diff --git a/drivers/gpu/drm/drm_probe_helper.c
> b/drivers/gpu/drm/drm_probe_helper.c
> index 09b12c30df69..f0474368e98d 100644
> --- a/drivers/gpu/drm/drm_probe_helper.c
> +++ b/drivers/gpu/drm/drm_probe_helper.c
> @@ -629,6 +629,8 @@ int drm_helper_probe_single_connector_modes(struct
> drm_connector *connector,
> mod_delayed_work(system_wq,
> &dev->mode_config.output_poll_work,
> 0);
> +
> + connector->status_changed = true;
.fill_modes() gets exectued from the getconnector() ioctl which userspace
issues in response to the uevent. Not the other way around. So looks
like you have the chicken and egg the wrong way around here.
> }
>
> /*
> @@ -732,6 +734,17 @@ EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
> */
> void drm_kms_helper_hotplug_event(struct drm_device *dev)
> {
> + struct drm_connector *connector;
> + struct drm_connector_list_iter conn_iter;
> +
> + mutex_lock(&dev->mode_config.mutex);
> + drm_connector_list_iter_begin(dev, &conn_iter);
> + drm_for_each_connector_iter(connector, &conn_iter) {
> + connector->status_changed = false;
> + }
> + drm_connector_list_iter_end(&conn_iter);
> + mutex_unlock(&dev->mode_config.mutex);
> +
> drm_sysfs_hotplug_event(dev);
> drm_client_dev_hotplug(dev);
> }
> @@ -748,6 +761,10 @@ void drm_kms_helper_connector_hotplug_event(struct
> drm_connector *connector)
> {
> struct drm_device *dev = connector->dev;
>
> + mutex_lock(&dev->mode_config.mutex);
> + connector->status_changed = false;
> + mutex_unlock(&dev->mode_config.mutex);
> +
> drm_sysfs_connector_hotplug_event(connector);
> drm_client_dev_hotplug(dev);
> }
> diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> index b01ffa4d6509..bd9161490116 100644
> --- a/drivers/gpu/drm/drm_sysfs.c
> +++ b/drivers/gpu/drm/drm_sysfs.c
> @@ -199,6 +199,7 @@ static ssize_t status_store(struct device *device,
> return ret;
>
> old_force = connector->force;
> + connector->status_changed = true;
>
> if (sysfs_streq(buf, "detect"))
> connector->force = 0;
> diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c
> b/drivers/gpu/drm/vkms/vkms_configfs.c
> index 506666e21c91..6d6dd1a2c3a6 100644
> --- a/drivers/gpu/drm/vkms/vkms_configfs.c
> +++ b/drivers/gpu/drm/vkms/vkms_configfs.c
> @@ -537,8 +537,14 @@ static ssize_t connector_status_store(struct config_item
> *item,
> {
> struct vkms_configfs_connector *connector;
> enum drm_connector_status status;
> + struct vkms_connector *vkms_connector;
> + struct vkms_device *vkms_dev;
>
> connector = connector_item_to_vkms_configfs_connector(item);
> + vkms_connector = connector->config->connector;
> + vkms_dev = connector->config->config->dev;
> + scoped_guard(mutex, &vkms_dev->drm.mode_config.mutex)
> + vkms_connector->base.status_changed = true;
>
> if (kstrtouint(page, 10, &status))
> return -EINVAL;
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 8f34f4b8183d..e4310df3d55c 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -2146,6 +2146,9 @@ struct drm_connector {
> /** @force: a DRM_FORCE_<foo> state for forced mode sets */
> enum drm_connector_force force;
>
> + /** @status_changed: if the old status doesn't match current connection
> status */
> + bool status_changed;
> +
> /**
> * @edid_override: Override EDID set via debugfs.
> *
> --
> 2.47.2
--
Ville Syrjälä
Intel
