diff --git a/adb/adb.c b/adb/adb.c
index 203e7d2..956df54 100644
--- a/adb/adb.c
+++ b/adb/adb.c
@@ -23,6 +23,7 @@
 #include <errno.h>
 #include <string.h>
 #include <time.h>
+#include <sys/time.h>
 
 #include "sysdeps.h"
 #include "adb.h"
@@ -657,10 +658,25 @@
 void start_device_log(void)
 {
     int fd;
-    char    path[100];
+    char    path[PATH_MAX];
+    struct tm now;
+    time_t t;
+    char value[PROPERTY_VALUE_MAX];
 
-    snprintf(path, sizeof path, "/data/adb_%ld.txt", (long)time(NULL));
-    fd = unix_open(path, O_WRONLY | O_CREAT | O_APPEND, 0640);
+    // read the trace mask from persistent property persist.adb.trace_mask
+    // give up if the property is not set or cannot be parsed
+    property_get("persist.adb.trace_mask", value, "");
+    if (sscanf(value, "%x", &adb_trace_mask) != 1)
+        return;
+
+    adb_mkdir("/data/adb", 0775);
+    tzset();
+    time(&t);
+    localtime_r(&t, &now);
+    strftime(path, sizeof(path),
+                "/data/adb/adb-%Y-%m-%d-%H-%M-%S.txt",
+                &now);
+    fd = unix_open(path, O_WRONLY | O_CREAT | O_TRUNC, 0640);
     if (fd < 0)
         return;
 
@@ -671,11 +687,6 @@
 
     fd = unix_open("/dev/null", O_RDONLY);
     dup2(fd, 0);
-
-    // log everything
-    adb_trace_mask = ~0;
-    // except TRACE_RWX is a bit too verbose
-    adb_trace_mask &= ~TRACE_RWX;
 }
 #endif
 
@@ -1079,9 +1090,8 @@
         adb_device_banner = "recovery";
         recovery_mode = 1;
     }
-#if ADB_DEVICE_LOG
+
     start_device_log();
-#endif
     return adb_main(0);
 #endif
 }
diff --git a/adb/adb.h b/adb/adb.h
index 3c4fe60..b9ed556 100644
--- a/adb/adb.h
+++ b/adb/adb.h
@@ -345,11 +345,6 @@
 #endif
 
 
-/* set this to log to /data/adb/adb_<time>.txt on the device.
- * has no effect if the /data/adb/ directory does not exist.
- */
-#define ADB_DEVICE_LOG 0
-
 #if !TRACE_PACKETS
 #define print_packet(tag,p) do {} while (0)
 #endif