[PATCH v8 21/29] drm/msm/dp: add HPD callback for dp MST
From: Yongxing Mou
Date: Tue Nov 10 2026 - 00:02:11 EST
From: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Add HPD callback for the MST module which shall be invoked from the
dp_display's HPD handler to perform MST specific operations in case
of HPD. In MST case, route the HPD messages to MST module.
Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Signed-off-by: Yongxing Mou <yongxing.mou@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_display.c | 21 ++++++++++++----
drivers/gpu/drm/msm/dp/dp_mst_drm.c | 48 +++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/msm/dp/dp_mst_drm.h | 1 +
3 files changed, 65 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index af8d22fd4fc5..b4e788d1f611 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -529,6 +529,11 @@ static int msm_dp_irq_hpd_handle(struct msm_dp_display_private *dp)
dp->msm_dp_display.connector_type,
dp->link->sink_count);
+ if (dp->msm_dp_display.mst_active) {
+ msm_dp_mst_display_hpd_irq(&dp->msm_dp_display);
+ return 0;
+ }
+
/* check for any test request issued by sink */
rc = msm_dp_link_process_request(dp->link);
if (!rc) {
@@ -1078,10 +1083,10 @@ static irqreturn_t msm_dp_display_irq_thread(int irq, void *dev_id)
drm_bridge_hpd_notify(dp->msm_dp_display.bridge,
connector_status_connected);
- /* Send HPD as connected and distinguish it in the notifier */
if (hpd_isr_status & DP_DP_IRQ_HPD_INT_MASK)
- drm_bridge_hpd_notify(dp->msm_dp_display.bridge,
- connector_status_connected);
+ drm_bridge_hpd_notify_extra(dp->msm_dp_display.bridge,
+ connector_status_connected,
+ DRM_CONNECTOR_DP_IRQ_HPD);
ret = IRQ_HANDLED;
@@ -1318,9 +1323,15 @@ int msm_dp_mst_register(struct msm_dp *msm_dp_display)
void msm_dp_mst_unregister(struct msm_dp *msm_dp_display)
{
+ struct msm_dp_display_private *dp;
+
if (!msm_dp_display->msm_dp_mst)
return;
+ dp = container_of(msm_dp_display, struct msm_dp_display_private, msm_dp_display);
+
+ /* HPD is disabled by drm_kms_helper_poll_fini() before KMS teardown. */
+ synchronize_irq(dp->irq);
msm_dp_mst_mgr_destroy(msm_dp_display);
}
@@ -1755,7 +1766,7 @@ void msm_dp_bridge_hpd_notify(struct drm_bridge *bridge,
struct msm_dp_bridge *msm_dp_bridge = to_dp_bridge(bridge);
struct msm_dp *msm_dp_display = msm_dp_bridge->msm_dp_display;
struct msm_dp_display_private *dp = container_of(msm_dp_display, struct msm_dp_display_private, msm_dp_display);
- u32 hpd_link_status = 0;
+ u32 hpd_link_status;
if (pm_runtime_resume_and_get(&msm_dp_display->pdev->dev)) {
DRM_ERROR("failed to pm_runtime_resume\n");
@@ -1778,7 +1789,7 @@ void msm_dp_bridge_hpd_notify(struct drm_bridge *bridge,
if (hpd_link_status == ISR_IRQ_HPD_PULSE_COUNT ||
event == DRM_CONNECTOR_DP_IRQ_HPD)
msm_dp_irq_hpd_handle(dp);
- } else {
+ } else if (status == connector_status_disconnected) {
msm_dp_hpd_unplug_handle(dp);
}
diff --git a/drivers/gpu/drm/msm/dp/dp_mst_drm.c b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
index eae82e857c84..15405080107f 100644
--- a/drivers/gpu/drm/msm/dp/dp_mst_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_mst_drm.c
@@ -15,6 +15,8 @@
#define to_dp_mst_connector(x) \
container_of((x), struct msm_dp_mst_connector, connector)
+#define MSM_DP_MST_HPD_IRQ_MAX_TRIES 30
+
struct msm_dp_mst_connector {
struct drm_connector connector;
struct drm_dp_mst_port *mst_port;
@@ -36,6 +38,8 @@ struct msm_dp_mst {
u32 max_streams;
/* Serializes concurrent stream link-state access across streams. */
struct mutex mst_lock;
+ /* Serializes HPD IRQ handling between IRQ handler and poll_hpd_irq. */
+ struct mutex hpd_irq_lock;
};
static void dp_mst_connector_destroy(struct drm_connector *connector)
@@ -358,6 +362,40 @@ int msm_dp_mst_attach_encoder(struct msm_dp *dp_display, unsigned int stream_id,
return 0;
}
+void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display)
+{
+ int rc;
+ struct msm_dp_mst *mst = dp_display->msm_dp_mst;
+ unsigned int esi_res = DP_SINK_COUNT_ESI + 1;
+ int i;
+
+ guard(mutex)(&mst->hpd_irq_lock);
+
+ for (i = 0; i < MSM_DP_MST_HPD_IRQ_MAX_TRIES; i++) {
+ u8 ack[8] = {};
+ u8 esi[4];
+ bool handled;
+
+ rc = drm_dp_dpcd_read_data(mst->dp_aux, DP_SINK_COUNT_ESI, esi, 4);
+ if (rc < 0) {
+ DRM_ERROR("DPCD sink status read failed, rlen=%d\n", rc);
+ return;
+ }
+
+ rc = drm_dp_mst_hpd_irq_handle_event(&mst->mst_mgr, esi, ack, &handled);
+ if (!handled)
+ break;
+
+ rc = drm_dp_dpcd_write_byte(mst->dp_aux, esi_res, ack[1]);
+ if (rc < 0) {
+ DRM_ERROR("DPCD esi_res failed. rc=%d\n", rc);
+ return;
+ }
+
+ drm_dp_mst_hpd_irq_send_new_request(&mst->mst_mgr);
+ }
+}
+
static struct drm_encoder *
msm_dp_mst_atomic_best_encoder(struct drm_connector *connector, struct drm_atomic_commit *state)
{
@@ -473,8 +511,16 @@ msm_dp_mst_add_connector(struct drm_dp_mst_topology_mgr *mgr,
return NULL;
}
+static void msm_dp_mst_poll_hpd_irq(struct drm_dp_mst_topology_mgr *mgr)
+{
+ struct msm_dp_mst *mst = container_of(mgr, struct msm_dp_mst, mst_mgr);
+
+ msm_dp_mst_display_hpd_irq(mst->msm_dp);
+}
+
static const struct drm_dp_mst_topology_cbs msm_dp_mst_drm_cbs = {
.add_connector = msm_dp_mst_add_connector,
+ .poll_hpd_irq = msm_dp_mst_poll_hpd_irq,
};
int msm_dp_mst_mgr_init(struct msm_dp *dp_display, struct msm_dp_link *link,
@@ -506,6 +552,7 @@ int msm_dp_mst_mgr_init(struct msm_dp *dp_display, struct msm_dp_link *link,
}
mutex_init(&mst->mst_lock);
+ mutex_init(&mst->hpd_irq_lock);
dp_display->msm_dp_mst = mst;
return 0;
}
@@ -518,6 +565,7 @@ void msm_dp_mst_mgr_destroy(struct msm_dp *dp_display)
return;
drm_dp_mst_topology_mgr_destroy(&mst->mst_mgr);
+ mutex_destroy(&mst->hpd_irq_lock);
mutex_destroy(&mst->mst_lock);
dp_display->msm_dp_mst = NULL;
kfree(mst);
diff --git a/drivers/gpu/drm/msm/dp/dp_mst_drm.h b/drivers/gpu/drm/msm/dp/dp_mst_drm.h
index 822d34cd6ff5..3bd3e66b4eac 100644
--- a/drivers/gpu/drm/msm/dp/dp_mst_drm.h
+++ b/drivers/gpu/drm/msm/dp/dp_mst_drm.h
@@ -12,5 +12,6 @@ int msm_dp_mst_mgr_init(struct msm_dp *dp_display, struct msm_dp_link *link,
void msm_dp_mst_mgr_destroy(struct msm_dp *dp_display);
int msm_dp_mst_attach_encoder(struct msm_dp *dp_display, unsigned int stream_id,
struct drm_encoder *encoder);
+void msm_dp_mst_display_hpd_irq(struct msm_dp *dp_display);
#endif /* _DP_MST_DRM_H_ */
--
2.43.0