Fixed #290: improved blank diagnostics

src/libs/capture.c

@@ -48,6 +48,7 @@
 #include "threading.h"
 #include "frame.h"
 #include "xioctl.h"
+#include "tc358743.h"
 
 
 static const struct {
@@ -200,11 +201,11 @@ int us_capture_open(us_capture_s *cap) {
 			}
 		}
 		_LOG_DEBUG("Probing DV-timings or QuerySTD ...");
-		if (_capture_open_dv_timings(cap, false) < 0) {
-			US_ONCE_FOR(run->open_error_once, __LINE__, {
-				_LOG_ERROR("No signal from source");
-			});
-			goto error_no_signal;
+		switch (_capture_open_dv_timings(cap, false)) {
+			case 0: break;
+			case US_ERROR_NO_SIGNAL: goto error_no_signal;
+			case US_ERROR_NO_SYNC: goto error_no_sync;
+			default: goto error;
 		}
 	}
 
@@ -222,6 +223,15 @@ int us_capture_open(us_capture_s *cap) {
 	if (_capture_open_format(cap, true) < 0) {
 		goto error;
 	}
+	if (cap->dv_timings && cap->persistent) {
+		struct v4l2_control ctl = {.id = TC358743_CID_LANES_ENOUGH};
+		if (!us_xioctl(run->fd, VIDIOC_G_CTRL, &ctl)) {
+			if (!ctl.value) {
+				_LOG_ERROR("Not enough lanes, hardware can't handle this signal");
+				goto error_no_lanes;
+			}
+		}
+	}
 	_capture_open_hw_fps(cap);
 	_capture_open_jpeg_quality(cap);
 	if (_capture_open_io_method(cap) < 0) {
@@ -259,8 +269,18 @@ error_no_cable:
 	return US_ERROR_NO_CABLE;
 
 error_no_signal:
+	US_ONCE_FOR(run->open_error_once, __LINE__, { _LOG_ERROR("No signal from source"); });
 	us_capture_close(cap);
-	return US_ERROR_NO_DATA;
+	return US_ERROR_NO_SIGNAL;
+
+error_no_sync:
+	US_ONCE_FOR(run->open_error_once, __LINE__, { _LOG_ERROR("No sync on signal"); });
+	us_capture_close(cap);
+	return US_ERROR_NO_SYNC;
+
+error_no_lanes:
+	us_capture_close(cap);
+	return US_ERROR_NO_LANES;
 
 error:
 	run->open_error_once = 0;
@@ -630,6 +650,10 @@ static int _capture_open_dv_timings(us_capture_s *cap, bool apply) {
 		// TC358743 errors here (see in the kernel: drivers/media/i2c/tc358743.c):
 		//   - ENOLINK: No valid signal (SYS_STATUS & MASK_S_TMDS)
 		//   - ENOLCK:  No sync on signal (SYS_STATUS & MASK_S_SYNC)
+		switch (errno) {
+			case ENOLINK: return US_ERROR_NO_SIGNAL;
+			case ENOLCK: return US_ERROR_NO_SYNC;
+		}
 		dv_errno = errno;
 		goto querystd;
 	} else if (!apply) {

src/libs/drm/drm.c

@@ -378,7 +378,7 @@ int us_drm_expose_stub(us_drm_s *drm, us_drm_stub_e stub, const us_capture_s *ca
 			DRAW_MSG("=== PiKVM ===\n \n< UNSUPPORTED CAPTURE FORMAT >");
 			break;
 		case US_DRM_STUB_NO_SIGNAL:
-			DRAW_MSG("=== PiKVM ===\n \n< NO SIGNAL >");
+			DRAW_MSG("=== PiKVM ===\n \n< NO LIVE VIDEO >");
 			break;
 		case US_DRM_STUB_BUSY:
 			DRAW_MSG("=== PiKVM ===\n \n< ONLINE IS ACTIVE >");

src/libs/errors.h

@@ -25,4 +25,7 @@
 #define US_ERROR_COMMON		-1
 #define US_ERROR_NO_DEVICE	-2
 #define US_ERROR_NO_CABLE	-3
-#define US_ERROR_NO_DATA	-4
+#define US_ERROR_NO_SIGNAL	-4
+#define US_ERROR_NO_SYNC	-5
+#define US_ERROR_NO_LANES	-6
+#define US_ERROR_NO_DATA	-7

src/libs/tc358743.c

@@ -33,17 +33,6 @@
 #include "xioctl.h"
 
 
-#ifndef V4L2_CID_USER_TC358743_BASE
-#	define V4L2_CID_USER_TC358743_BASE (V4L2_CID_USER_BASE + 0x1080)
-#endif
-#ifndef TC358743_CID_AUDIO_PRESENT
-#	define TC358743_CID_AUDIO_PRESENT (V4L2_CID_USER_TC358743_BASE + 1)
-#endif
-#ifndef TC358743_CID_AUDIO_SAMPLING_RATE
-#	define TC358743_CID_AUDIO_SAMPLING_RATE (V4L2_CID_USER_TC358743_BASE + 0)
-#endif
-
-
 int us_tc358743_xioctl_get_audio_hz(int fd, uint *audio_hz) {
 	*audio_hz = 0;
 

src/libs/tc358743.h

@@ -22,7 +22,26 @@
 
 #pragma once
 
+#include <linux/v4l2-controls.h>
+
 #include "types.h"
 
 
+#ifndef V4L2_CID_USER_TC358743_BASE
+#	define V4L2_CID_USER_TC358743_BASE (V4L2_CID_USER_BASE + 0x1080)
+#endif
+
+#ifndef TC358743_CID_AUDIO_SAMPLING_RATE
+#	define TC358743_CID_AUDIO_SAMPLING_RATE (V4L2_CID_USER_TC358743_BASE + 0)
+#endif
+
+#ifndef TC358743_CID_AUDIO_PRESENT
+#	define TC358743_CID_AUDIO_PRESENT (V4L2_CID_USER_TC358743_BASE + 1)
+#endif
+
+#ifndef TC358743_CID_LANES_ENOUGH
+#	define TC358743_CID_LANES_ENOUGH (V4L2_CID_USER_TC358743_BASE + 2)
+#endif
+
+
 int us_tc358743_xioctl_get_audio_hz(int fd, uint *audio_hz);