From 2d9e51a1ca9f832641e01b74d1f3b1f84d2ec152 Mon Sep 17 00:00:00 2001
From: Maxim Devaev <mdevaev@gmail.com>
Date: Sun, 10 Mar 2024 17:10:42 +0200
Subject: [PATCH] v4p: turn off the display after timeout

---
 src/v4p/drm.c  |  5 ++++-
 src/v4p/main.c | 23 +++++++++++++++++------
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/v4p/drm.c b/src/v4p/drm.c
index dbcfcc5..6752a5b 100644
--- a/src/v4p/drm.c
+++ b/src/v4p/drm.c
@@ -244,7 +244,10 @@ int us_drm_dpms_power_off(us_drm_s *drm) {
 	assert(drm->run->fd >= 0);
 	switch (_drm_check_status(drm)) {
 		case 0: break;
-		case -2: return -2;
+		case -2: return 0; // Unplugged, nice
+		// Во время переключения DPMS монитор моргает один раз состоянием disconnected,
+		// а потом почему-то снова оказывается connected. Так что просто считаем,
+		// что отсоединенный монитор на этом этапе - это нормально.
 		default: return -1;
 	}
 	_drm_ensure_dpms_power(drm, false);
diff --git a/src/v4p/main.c b/src/v4p/main.c
index 8cb58af..a301716 100644
--- a/src/v4p/main.c
+++ b/src/v4p/main.c
@@ -172,17 +172,20 @@ static void _main_loop(void) {
 	dev->dma_required = true;
 
 	int once = 0;
+	ldf blank_at_ts = 0;
 	int drm_opened = -1;
 	while (!atomic_load(&_g_stop)) {
 #		define CHECK(x_arg) if ((x_arg) < 0) { goto close; }
 
 		if (drm_opened <= 0) {
+			blank_at_ts = 0;
 			CHECK(drm_opened = us_drm_open(drm, NULL));
 		}
 		assert(drm_opened > 0);
 
 		if (atomic_load(&_g_ustreamer_online)) {
-			US_ONCE({ US_LOG_ERROR("DRM: Online stream is active, stopping capture ..."); });
+			blank_at_ts = 0;
+			US_ONCE({ US_LOG_INFO("DRM: Online stream is active, stopping capture ..."); });
 			CHECK(us_drm_wait_for_vsync(drm));
 			CHECK(us_drm_expose_stub(drm, US_DRM_STUB_BUSY, NULL));
 			_slowdown();
@@ -190,18 +193,26 @@ static void _main_loop(void) {
 		}
 
 		if (us_device_open(dev) < 0) {
-			/*CHECK(us_drm_wait_for_vsync(drm));
-			CHECK(us_drm_expose_stub(drm, US_DRM_STUB_NO_SIGNAL, NULL));*/
-			CHECK(us_drm_dpms_power_off(drm));
+			ldf now_ts = us_get_now_monotonic();
+			if (blank_at_ts == 0) {
+				blank_at_ts = now_ts + 5;
+			}
+			if (now_ts <= blank_at_ts) {
+				CHECK(us_drm_wait_for_vsync(drm));
+				CHECK(us_drm_expose_stub(drm, US_DRM_STUB_NO_SIGNAL, NULL));
+			} else {
+				US_ONCE({ US_LOG_INFO("DRM: Turning off the display by timeout ..."); });
+				CHECK(us_drm_dpms_power_off(drm));
+			}
 			_slowdown();
 			continue;
 		}
 
+		once = 0;
+		blank_at_ts = 0;
 		us_drm_close(drm);
 		CHECK(drm_opened = us_drm_open(drm, dev));
 
-		once = 0;
-
 		us_hw_buffer_s *prev_hw = NULL;
 		while (!atomic_load(&_g_stop)) {
 			if (atomic_load(&_g_ustreamer_online)) {