fix: update power saving mode condition to include zero duration

V4L2 buffers were not explicitly freed before closing the device, causing VIDIOC_S_FMT to fail with EBUSY on restart. Added  VIDIOC_REQBUFS(count=0) call in cleanup to free buffer queue synchronously before close().

This ensures subsequent opens can set format immediately without EBUSY errors, eliminating 100ms+ retry delays.

config.go

@@ -106,6 +106,7 @@ type Config struct {
 	NetworkConfig        *types.NetworkConfig `json:"network_config"`
 	DefaultLogLevel      string               `json:"default_log_level"`
 	VideoSleepAfterSec   int                  `json:"video_sleep_after_sec"`
+	VideoQualityFactor   float64              `json:"video_quality_factor"`
 }
 
 func (c *Config) GetDisplayRotation() uint16 {

internal/native/cgo/ctrl.c

@@ -405,8 +405,8 @@ char *jetkvm_video_log_status() {
     return (char *)videoc_log_status();
 }
 
-int jetkvm_video_init() {
+int jetkvm_video_init(float factor) {
-    return video_init();
+    return video_init(factor);
 }
 
 void jetkvm_video_shutdown() {

internal/native/cgo/ctrl.h

@@ -52,7 +52,7 @@ const char *jetkvm_ui_get_lvgl_version();
 
 const char *jetkvm_ui_event_code_to_name(int code);
 
-int jetkvm_video_init();
+int jetkvm_video_init(float quality_factor);
 void jetkvm_video_shutdown();
 void jetkvm_video_start();
 void jetkvm_video_stop();

internal/native/cgo/video.c

@@ -66,9 +66,20 @@ static void ensure_sleep_mode_disabled()
         log_error("Failed to open sleep mode file: %s", strerror(errno));
         return;
     }
+    lseek(fd, 0, SEEK_SET);
+    char buffer[1];
+    read(fd, buffer, 1);
+    if (buffer[0] == '0') {
+        close(fd);
+        return;
+    }
+    log_warn("HDMI sleep mode is not disabled, disabling it");
+    lseek(fd, 0, SEEK_SET);
     write(fd, "0", 1);
     close(fd);
 
+    usleep(1000); // give some time to the system to disable the sleep mode
+    return;
 }
 
 static void detect_sleep_mode()
@@ -220,10 +231,15 @@ static int32_t buf_init()
 
 pthread_t *format_thread = NULL;
 
-int video_init()
+int video_init(float factor)
 {
     detect_sleep_mode();
 
+    if (factor < 0 || factor > 1) {
+        factor = 1.0f;
+    }
+    quality_factor = factor;
+
     if (RK_MPI_SYS_Init() != RK_SUCCESS)
     {
         log_error("RK_MPI_SYS_Init failed");
@@ -590,6 +606,18 @@ void *run_video_stream(void *arg)
             log_error("VIDIOC_STREAMOFF failed: %s", strerror(errno));
         }
 
+        // Explicitly free V4L2 buffer queue
+        struct v4l2_requestbuffers req_free;
+        memset(&req_free, 0, sizeof(req_free));
+        req_free.count = 0;
+        req_free.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+        req_free.memory = V4L2_MEMORY_DMABUF;
+
+        if (ioctl(video_dev_fd, VIDIOC_REQBUFS, &req_free) < 0)
+        {
+            log_error("Failed to free V4L2 buffers: %s", strerror(errno));
+        }
+
         venc_stop();
 
         for (int i = 0; i < input_buffer_count; i++)
@@ -765,12 +793,18 @@ void *run_detect_format(void *arg)
                                         (dv_timings.bt.width + dv_timings.bt.hfrontporch + dv_timings.bt.hsync +
                                          dv_timings.bt.hbackporch));
             log_info("Frames per second: %.2f fps", frames_per_second);
+
+            bool should_restart = dv_timings.bt.width != detected_width || dv_timings.bt.height != detected_height || !detected_signal;
+
             detected_width = dv_timings.bt.width;
             detected_height = dv_timings.bt.height;
             detected_signal = true;
             video_report_format(true, NULL, detected_width, detected_height, frames_per_second);
 
-            video_restart_streaming();
+            if (should_restart) {
+                log_info("restarting video streaming due to format change");
+                video_restart_streaming();
+            }
         }
 
         memset(&ev, 0, sizeof(ev));

internal/native/cgo/video.h

@@ -6,7 +6,7 @@
  *
  * @return int 0 on success, -1 on failure
  */
-int video_init();
+int video_init(float quality_factor);
 
 /**
  * @brief Shutdown the video subsystem

internal/native/cgo_linux.go

@@ -129,11 +129,13 @@ func uiTick() {
 	C.jetkvm_ui_tick()
 }
 
-func videoInit() error {
+func videoInit(factor float64) error {
 	cgoLock.Lock()
 	defer cgoLock.Unlock()
 
-	ret := C.jetkvm_video_init()
+	factorC := C.float(factor)
+
+	ret := C.jetkvm_video_init(factorC)
 	if ret != 0 {
 		return fmt.Errorf("failed to initialize video: %d", ret)
 	}

internal/native/native.go

@@ -15,6 +15,7 @@ type Native struct {
 	systemVersion        *semver.Version
 	appVersion           *semver.Version
 	displayRotation      uint16
+	defaultQualityFactor float64
 	onVideoStateChange   func(state VideoState)
 	onVideoFrameReceived func(frame []byte, duration time.Duration)
 	onIndevEvent         func(event string)
@@ -22,12 +23,14 @@ type Native struct {
 	sleepModeSupported   bool
 	videoLock            sync.Mutex
 	screenLock           sync.Mutex
+	extraLock            sync.Mutex
 }
 
 type NativeOptions struct {
 	SystemVersion        *semver.Version
 	AppVersion           *semver.Version
 	DisplayRotation      uint16
+	DefaultQualityFactor float64
 	OnVideoStateChange   func(state VideoState)
 	OnVideoFrameReceived func(frame []byte, duration time.Duration)
 	OnIndevEvent         func(event string)
@@ -65,6 +68,11 @@ func NewNative(opts NativeOptions) *Native {
 
 	sleepModeSupported := isSleepModeSupported()
 
+	defaultQualityFactor := opts.DefaultQualityFactor
+	if defaultQualityFactor < 0 || defaultQualityFactor > 1 {
+		defaultQualityFactor = 1.0
+	}
+
 	return &Native{
 		ready:                make(chan struct{}),
 		l:                    nativeLogger,
@@ -72,6 +80,7 @@ func NewNative(opts NativeOptions) *Native {
 		systemVersion:        opts.SystemVersion,
 		appVersion:           opts.AppVersion,
 		displayRotation:      opts.DisplayRotation,
+		defaultQualityFactor: defaultQualityFactor,
 		onVideoStateChange:   onVideoStateChange,
 		onVideoFrameReceived: onVideoFrameReceived,
 		onIndevEvent:         onIndevEvent,
@@ -97,7 +106,7 @@ func (n *Native) Start() {
 	n.initUI()
 	go n.tickUI()
 
-	if err := videoInit(); err != nil {
+	if err := videoInit(n.defaultQualityFactor); err != nil {
 		n.l.Error().Err(err).Msg("failed to initialize video")
 	}
 

internal/native/video.go

@@ -1,7 +1,9 @@
 package native
 
 import (
+	"fmt"
 	"os"
+	"time"
 )
 
 const sleepModeFile = "/sys/devices/platform/ff470000.i2c/i2c-4/4-000f/sleep_mode"
@@ -9,6 +11,8 @@ const sleepModeFile = "/sys/devices/platform/ff470000.i2c/i2c-4/4-000f/sleep_mod
 // DefaultEDID is the default EDID for the video stream.
 const DefaultEDID = "00ffffffffffff0052620188008888881c150103800000780a0dc9a05747982712484c00000001010101010101010101010101010101023a801871382d40582c4500c48e2100001e011d007251d01e206e285500c48e2100001e000000fc00543734392d6648443732300a20000000fd00147801ff1d000a202020202020017b"
 
+var extraLockTimeout = 5 * time.Second
+
 // VideoState is the state of the video stream.
 type VideoState struct {
 	Ready          bool    `json:"ready"`
@@ -69,12 +73,32 @@ func (n *Native) VideoSleepModeSupported() bool {
 	return n.sleepModeSupported
 }
 
+// useExtraLock uses the extra lock to execute a function.
+// if the lock is currently held by another goroutine, returns an error.
+//
+// it's used to ensure that only one change is made to the video stream at a time.
+// as the change usually requires to restart video streaming
+// TODO: check video streaming status instead of using a hardcoded timeout
+func (n *Native) useExtraLock(fn func() error) error {
+	if !n.extraLock.TryLock() {
+		return fmt.Errorf("the previous change hasn't been completed yet")
+	}
+	err := fn()
+	if err == nil {
+		time.Sleep(extraLockTimeout)
+	}
+	n.extraLock.Unlock()
+	return err
+}
+
 // VideoSetQualityFactor sets the quality factor for the video stream.
 func (n *Native) VideoSetQualityFactor(factor float64) error {
 	n.videoLock.Lock()
 	defer n.videoLock.Unlock()
 
-	return videoSetStreamQualityFactor(factor)
+	return n.useExtraLock(func() error {
+		return videoSetStreamQualityFactor(factor)
+	})
 }
 
 // VideoGetQualityFactor gets the quality factor for the video stream.
@@ -94,7 +118,9 @@ func (n *Native) VideoSetEDID(edid string) error {
 		edid = DefaultEDID
 	}
 
-	return videoSetEDID(edid)
+	return n.useExtraLock(func() error {
+		return videoSetEDID(edid)
+	})
 }
 
 // VideoGetEDID gets the EDID for the video stream.

native.go

@@ -17,9 +17,10 @@ var (
 
 func initNative(systemVersion *semver.Version, appVersion *semver.Version) {
 	nativeInstance = native.NewNative(native.NativeOptions{
-		SystemVersion:   systemVersion,
+		SystemVersion:        systemVersion,
-		AppVersion:      appVersion,
+		AppVersion:           appVersion,
-		DisplayRotation: config.GetDisplayRotation(),
+		DisplayRotation:      config.GetDisplayRotation(),
+		DefaultQualityFactor: config.VideoQualityFactor,
 		OnVideoStateChange: func(state native.VideoState) {
 			lastVideoState = state
 			triggerVideoStateUpdate()
@@ -60,9 +61,11 @@ func initNative(systemVersion *semver.Version, appVersion *semver.Version) {
 	})
 
 	nativeInstance.Start()
-	if err := nativeInstance.VideoSetEDID(config.EdidString); err != nil {
+	go func() {
-		nativeLogger.Warn().Err(err).Msg("error setting EDID")
+		if err := nativeInstance.VideoSetEDID(config.EdidString); err != nil {
-	}
+			nativeLogger.Warn().Err(err).Msg("error setting EDID")
+		}
+	}()
 
 	if os.Getenv("JETKVM_CRASH_TESTING") == "1" {
 		nativeInstance.DoNotUseThisIsForCrashTestingOnly()

ui/src/routes/devices.$id.settings.hardware.tsx

@@ -95,7 +95,7 @@ export default function SettingsHardwareRoute() {
         return;
       }
       const result = resp.result as { enabled: boolean; duration: number };
-      setPowerSavingEnabled(result.duration > 0);
+      setPowerSavingEnabled(result.duration >= 0);
     });
   }, [send]);