Hi Dmitry,
On 9/20/2026 11:01 PM, Dmitry Baryshkov wrote:
> The DisplayPort standard defines a special kind of events called IRQ.
> These events are used to notify DP Source about the events on the Sink
> side. It is extremely important for DP MST handling, where the MST
> events are reported through this IRQ.
>
> In case of the USB-C DP AltMode there is no actual HPD pulse, but the
> events are reported through the bits in the AltMode VDOs.
>
> Rename drm_connector_oob_hotplug_event() to drm_connector_dp_oob_status()
> and extend its interface to report IRQ events to the DisplayPort Sink
> drivers.
>
> Acked-by: Heikki Krogerus <[email protected]>
> Signed-off-by: Dmitry Baryshkov <[email protected]>
> ---
> drivers/gpu/drm/drm_connector.c | 20 ++++++++++++--------
> drivers/usb/typec/altmodes/displayport.c | 23 +++++++++++++++--------
> include/drm/drm_connector.h | 21 +++++++++++++++++++--
> 3 files changed, 46 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 8b4baed060f3..5d4945ea1e95 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -3672,20 +3672,24 @@ struct drm_connector
> *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> }
>
> /**
> - * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to
> connector
> + * drm_connector_dp_oob_status - Report out-of-band hotplug event to
> DisplayPort connector
> * @connector_fwnode: fwnode_handle to report the event on
> * @status: hot plug detect logical state
> + * @event: additional event reported by the sink without changing the HPD
> state
> + * (or in addition to such a change).
> *
> - * On some hardware a hotplug event notification may come from outside the
> display
> - * driver / device. An example of this is some USB Type-C setups where the
> hardware
> - * muxes the DisplayPort data and aux-lines but does not pass the altmode HPD
> - * status bit to the GPU's DP HPD pin.
> + * In some cases when DisplayPort signals are being routed through the USB
> + * Type-C port the hotplug event notifications come from outside of the
> display
> + * driver / device. In this case hardware muxes the DisplayPort data and
> + * AUX-lines but does not pass the altmode HPD status bit to the GPU's DP HPD
> + * pin.
> *
> * This function can be used to report these out-of-band events after
> obtaining
> * a drm_connector reference through calling drm_connector_find_by_fwnode().
> */
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> - enum drm_connector_status status)
> +void drm_connector_dp_oob_status(struct fwnode_handle *connector_fwnode,
> + enum drm_connector_status status,
> + enum drm_connector_dp_event event)
> {
> struct drm_connector *connector;
>
> @@ -3698,7 +3702,7 @@ void drm_connector_oob_hotplug_event(struct
> fwnode_handle *connector_fwnode,
>
> drm_connector_put(connector);
> }
> -EXPORT_SYMBOL(drm_connector_oob_hotplug_event);
> +EXPORT_SYMBOL(drm_connector_dp_oob_status);
>
> /**
> * drm_connector_get_color_format - Return connector color format of
> @conn_state
> diff --git a/drivers/usb/typec/altmodes/displayport.c
> b/drivers/usb/typec/altmodes/displayport.c
> index 51c92dd887ab..344a13c2a296 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -187,9 +187,11 @@ static int dp_altmode_status_update(struct dp_altmode
> *dp)
> dp->pending_irq_hpd = true;
> }
> } else {
> - drm_connector_oob_hotplug_event(dp->connector_fwnode,
> + drm_connector_dp_oob_status(dp->connector_fwnode,
> hpd ?
> connector_status_connected :
> -
> connector_status_disconnected);
> +
> connector_status_disconnected,
> + (hpd && irq_hpd) ?
> DRM_CONNECTOR_DP_IRQ_HPD :
> +
> DRM_CONNECTOR_NO_EXTRA_STATUS);
The CI is complaining about the alignment issue here.
I think this needs to be fixed?
> dp->hpd = hpd;
> sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
> if (hpd && irq_hpd) {
> @@ -211,8 +213,11 @@ static int dp_altmode_configured(struct dp_altmode *dp)
> * configuration is complete to signal HPD.
> */
> if (dp->pending_hpd) {
> - drm_connector_oob_hotplug_event(dp->connector_fwnode,
> - connector_status_connected);
> + drm_connector_dp_oob_status(dp->connector_fwnode,
> + connector_status_connected,
> + dp->pending_irq_hpd ?
> + DRM_CONNECTOR_DP_IRQ_HPD :
> + DRM_CONNECTOR_NO_EXTRA_STATUS);
> sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
> dp->pending_hpd = false;
> if (dp->pending_irq_hpd) {
> @@ -396,8 +401,9 @@ static int dp_altmode_vdm(struct typec_altmode *alt,
> dp->data.status = 0;
> dp->data.conf = 0;
> if (dp->hpd) {
> -
> drm_connector_oob_hotplug_event(dp->connector_fwnode,
> -
> connector_status_disconnected);
> +
> drm_connector_dp_oob_status(dp->connector_fwnode,
> +
> connector_status_disconnected,
> +
> DRM_CONNECTOR_NO_EXTRA_STATUS);
> dp->hpd = false;
> sysfs_notify(&dp->alt->dev.kobj, "displayport",
> "hpd");
> }
> @@ -844,8 +850,9 @@ void dp_altmode_remove(struct typec_altmode *alt)
> typec_altmode_put_plug(dp->plug_prime);
>
> if (dp->connector_fwnode) {
> - drm_connector_oob_hotplug_event(dp->connector_fwnode,
> - connector_status_disconnected);
> + drm_connector_dp_oob_status(dp->connector_fwnode,
> + connector_status_disconnected,
> + DRM_CONNECTOR_NO_EXTRA_STATUS);
>
> fwnode_handle_put(dp->connector_fwnode);
> }
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index c61345e6fb08..906aaefca7e1 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -91,6 +91,22 @@ enum drm_connector_status {
> connector_status_unknown = 3,
> };
>
> +/**
> + * enum drm_connector_dp_event - additional events sent by the sink /
> + * display together or in replacement of the HPD status changes.
> + */
> +enum drm_connector_dp_event {
> + /**
> + * @DRM_CONNECTOR_NO_EXTRA_STATUS: No additional status reported.
> + */
> + DRM_CONNECTOR_NO_EXTRA_STATUS,
> + /**
> + * @DRM_CONNECTOR_DP_IRQ_HPD: DisplayPort Sink has sent the
> + * IRQ_HPD (either by the HPD short pulse or via the AltMode event).
> + */
> + DRM_CONNECTOR_DP_IRQ_HPD,
> +};
> +
> /**
> * enum drm_connector_registration_state - userspace registration status for
> * a &drm_connector
> @@ -2703,8 +2719,9 @@ drm_connector_is_unregistered(struct drm_connector
> *connector)
> DRM_CONNECTOR_UNREGISTERED;
> }
>
> -void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
> - enum drm_connector_status status);
> +void drm_connector_dp_oob_status(struct fwnode_handle *connector_fwnode,
> + enum drm_connector_status status,
> + enum drm_connector_dp_event event);
> enum drm_connector_color_format
> drm_connector_get_color_format(const struct drm_connector_state *conn_state);
> const char *drm_get_connector_type_name(unsigned int connector_type);
>
--
Best,
Chaoyi
