--- a/nix/patches/mainline/drm/canaan_dsi.c
+++ b/nix/patches/mainline/drm/canaan_dsi.c
@@ -28,0 +29 @@
+#include <drm/drm_device.h>
@@ -777,0 +779,27 @@
+/* GPIO23 is owned by touch. Read bridge HPD without claiming its IRQ and
+ * notify DRM promptly instead of waiting for the generic ten-second poll.
+ * Keep that generic poll as a fallback; emit events only on cable changes.
+ */
+static void canaan_dsi_hpd_work(struct work_struct *work)
+{
+	struct canaan_dsi *dsi = container_of(to_delayed_work(work),
+						struct canaan_dsi, hpd_work);
+	enum drm_connector_status status;
+
+	if (READ_ONCE(dsi->hpd_stopping))
+		return;
+	/* Binding precedes DRM registration and poll initialization. */
+	if (!READ_ONCE(dsi->drm->registered) ||
+	    !READ_ONCE(dsi->drm->mode_config.poll_enabled))
+		goto again;
+
+	status = drm_bridge_detect(dsi->bridge, &dsi->connector);
+	if (status != connector_status_unknown && status != dsi->hpd_status) {
+		drm_helper_hpd_irq_event(dsi->drm);
+		dsi->hpd_status = status;
+	}
+again:
+	if (!READ_ONCE(dsi->hpd_stopping))
+		schedule_delayed_work(&dsi->hpd_work, msecs_to_jiffies(250));
+}
+
@@ -815 +843,2 @@
-						DRM_CONNECTOR_POLL_DISCONNECT;
+						DRM_CONNECTOR_POLL_DISCONNECT |
+						DRM_CONNECTOR_POLL_HPD;
@@ -831,0 +861,2 @@
+		if (dsi->dual_output)
+			bridge_connector->polled |= DRM_CONNECTOR_POLL_HPD;
@@ -835,0 +867,5 @@
+	if (dsi->dual_output) {
+		dsi->hpd_status = connector_status_unknown;
+		WRITE_ONCE(dsi->hpd_stopping, false);
+		schedule_delayed_work(&dsi->hpd_work, msecs_to_jiffies(250));
+	}
@@ -843,0 +880,2 @@
+	WRITE_ONCE(dsi->hpd_stopping, true);
+	cancel_delayed_work_sync(&dsi->hpd_work);
@@ -873,0 +912 @@
+	INIT_DELAYED_WORK(&dsi->hpd_work, canaan_dsi_hpd_work);
--- a/nix/patches/mainline/drm/canaan_dsi.h
+++ b/nix/patches/mainline/drm/canaan_dsi.h
@@ -12,0 +13 @@
+#include <linux/workqueue.h>
@@ -42,0 +44,3 @@
+	struct delayed_work hpd_work;
+	enum drm_connector_status hpd_status;
+	bool hpd_stopping;