Hello Yongxing, On 6/29/2026 10:48 PM, Yongxing Mou wrote: > The bridge connector framework currently invokes all bridge > hpd_notify() callbacks and unconditionally emits a connector hotplug > event afterwards. > > However, not every HPD notification requires a userspace hotplug event. > > In particular, DP MST bridges may use hpd_notify() to propagate HPD and > IRQ notifications through the bridge chain while the actual hotplug > handling is performed by the DRM DP MST core. Connector creation, > removal and userspace hotplug events are already managed by the MST > topology framework. > > Allow hpd_notify() implementations to suppress the bridge connector > hotplug event by introducing a bool *send_hotplug parameter. Drivers > can clear this flag when HPD processing should not result in a > connector hotplug notification. > > A NULL pointer indicates that hotplug suppression is not supported by > the caller, such as the connector detect polling path. >
Should we add an API to distinguish between regular HPD events and the IRQ-only notifications you mentioned? I've recently seen similar approaches. For example, this patch[0] adds handling for internal events, which I think is somewhat similar to the IRQ-only notification here. [0]: https://lore.kernel.org/all/20260806-synopsys-dw-dp-improvements-v11-11-0d508505f...@collabora.com/ > Signed-off-by: Yongxing Mou <[email protected]> > --- > drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 3 ++- > drivers/gpu/drm/display/drm_bridge_connector.c | 15 +++++++++------ > drivers/gpu/drm/meson/meson_encoder_hdmi.c | 3 ++- > drivers/gpu/drm/msm/dp/dp_display.c | 3 ++- > drivers/gpu/drm/msm/dp/dp_drm.h | 3 ++- > drivers/gpu/drm/omapdrm/dss/hdmi4.c | 3 ++- > include/drm/drm_bridge.h | 3 ++- > 7 files changed, 21 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c > b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c > index 8cb17bd0e238..42e1cadcd3fb 100644 > --- a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c > +++ b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c > @@ -430,7 +430,8 @@ static const struct drm_edid > *lt9611uxc_bridge_edid_read(struct drm_bridge *brid > static void lt9611uxc_bridge_hpd_notify(struct drm_bridge *bridge, > struct drm_connector *connector, > enum drm_connector_status status, > - enum drm_connector_status_extra > extra_status) > + enum drm_connector_status_extra > extra_status, > + bool *send_hotplug) > { > const struct drm_edid *drm_edid; > > diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c > b/drivers/gpu/drm/display/drm_bridge_connector.c > index 8f7075fd2aa5..5edca47a025f 100644 > --- a/drivers/gpu/drm/display/drm_bridge_connector.c > +++ b/drivers/gpu/drm/display/drm_bridge_connector.c > @@ -142,7 +142,8 @@ struct drm_bridge_connector { > > static void drm_bridge_connector_hpd_notify(struct drm_connector *connector, > enum drm_connector_status status, > - enum drm_connector_status_extra > extra_status) > + enum drm_connector_status_extra > extra_status, > + bool *send_hotplug) > { > struct drm_bridge_connector *bridge_connector = > to_drm_bridge_connector(connector); > @@ -150,13 +151,14 @@ static void drm_bridge_connector_hpd_notify(struct > drm_connector *connector, > /* Notify all bridges in the pipeline of hotplug events. */ > drm_for_each_bridge_in_chain_scoped(bridge_connector->encoder, bridge) { > if (bridge->funcs->hpd_notify) > - bridge->funcs->hpd_notify(bridge, connector, status, > extra_status); > + bridge->funcs->hpd_notify(bridge, connector, status, > + extra_status, send_hotplug); > } > } > > static void drm_bridge_connector_handle_hpd(struct drm_bridge_connector > *drm_bridge_connector, > - enum drm_connector_status status, > - enum drm_connector_status_extra > extra_status) > + enum drm_connector_status status, > + enum drm_connector_status_extra extra_status) > { > struct drm_connector *connector = &drm_bridge_connector->base; > struct drm_device *dev = connector->dev; > @@ -165,7 +167,7 @@ static void drm_bridge_connector_handle_hpd(struct > drm_bridge_connector *drm_bri > connector->status = status; > mutex_unlock(&dev->mode_config.mutex); > > - drm_bridge_connector_hpd_notify(connector, status, extra_status); > + drm_bridge_connector_hpd_notify(connector, status, extra_status, NULL); > > drm_kms_helper_connector_hotplug_event(connector); > } > @@ -227,7 +229,8 @@ drm_bridge_connector_detect(struct drm_connector > *connector, bool force) > if (hdmi) > drm_atomic_helper_connector_hdmi_hotplug(connector, > status); > > - drm_bridge_connector_hpd_notify(connector, status, > DRM_CONNECTOR_NO_EXTRA_STATUS); > + drm_bridge_connector_hpd_notify(connector, status, > + DRM_CONNECTOR_NO_EXTRA_STATUS, > NULL); > } else { > switch (connector->connector_type) { > case DRM_MODE_CONNECTOR_DPI: > diff --git a/drivers/gpu/drm/meson/meson_encoder_hdmi.c > b/drivers/gpu/drm/meson/meson_encoder_hdmi.c > index 4aecf0ffcf75..a67e7b365c5b 100644 > --- a/drivers/gpu/drm/meson/meson_encoder_hdmi.c > +++ b/drivers/gpu/drm/meson/meson_encoder_hdmi.c > @@ -324,7 +324,8 @@ static int meson_encoder_hdmi_atomic_check(struct > drm_bridge *bridge, > static void meson_encoder_hdmi_hpd_notify(struct drm_bridge *bridge, > struct drm_connector *connector, > enum drm_connector_status status, > - enum drm_connector_status_extra > extra_status) > + enum drm_connector_status_extra > extra_status, > + bool *send_hotplug) > { > struct meson_encoder_hdmi *encoder_hdmi = > bridge_to_meson_encoder_hdmi(bridge); > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c > b/drivers/gpu/drm/msm/dp/dp_display.c > index fcfee26f0078..6835c68fe510 100644 > --- a/drivers/gpu/drm/msm/dp/dp_display.c > +++ b/drivers/gpu/drm/msm/dp/dp_display.c > @@ -1763,7 +1763,8 @@ void msm_dp_bridge_hpd_disable(struct drm_bridge > *bridge) > void msm_dp_bridge_hpd_notify(struct drm_bridge *bridge, > struct drm_connector *connector, > enum drm_connector_status status, > - enum drm_connector_status_extra extra_status) > + enum drm_connector_status_extra extra_status, > + bool *send_hotplug) > { > struct msm_dp_bridge *msm_dp_bridge = to_dp_bridge(bridge); > struct msm_dp *msm_dp_display = msm_dp_bridge->msm_dp_display; > diff --git a/drivers/gpu/drm/msm/dp/dp_drm.h b/drivers/gpu/drm/msm/dp/dp_drm.h > index f6b96c27408a..07ddcd055962 100644 > --- a/drivers/gpu/drm/msm/dp/dp_drm.h > +++ b/drivers/gpu/drm/msm/dp/dp_drm.h > @@ -32,6 +32,7 @@ void msm_dp_bridge_hpd_disable(struct drm_bridge *bridge); > void msm_dp_bridge_hpd_notify(struct drm_bridge *bridge, > struct drm_connector *connector, > enum drm_connector_status status, > - enum drm_connector_status_extra extra_status); > + enum drm_connector_status_extra extra_status, > + bool *send_hotplug); > > #endif /* _DP_DRM_H_ */ > diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi4.c > b/drivers/gpu/drm/omapdrm/dss/hdmi4.c > index d02d432abde4..ad659cef16f5 100644 > --- a/drivers/gpu/drm/omapdrm/dss/hdmi4.c > +++ b/drivers/gpu/drm/omapdrm/dss/hdmi4.c > @@ -430,7 +430,8 @@ static void hdmi4_bridge_disable(struct drm_bridge > *bridge, > static void hdmi4_bridge_hpd_notify(struct drm_bridge *bridge, > struct drm_connector *connector, > enum drm_connector_status status, > - enum drm_connector_status_extra > extra_status) > + enum drm_connector_status_extra > extra_status, > + bool *send_hotplug) > { > struct omap_hdmi *hdmi = drm_bridge_to_hdmi(bridge); > > diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h > index 9c4c88024cc5..e6de665ce8f6 100644 > --- a/include/drm/drm_bridge.h > +++ b/include/drm/drm_bridge.h > @@ -616,7 +616,8 @@ struct drm_bridge_funcs { > void (*hpd_notify)(struct drm_bridge *bridge, > struct drm_connector *connector, > enum drm_connector_status status, > - enum drm_connector_status_extra extra_status); > + enum drm_connector_status_extra extra_status, > + bool *send_hotplug); > > /** > * @hpd_enable: > -- Best, Chaoyi
