monitor-get-edid-using-vbe:

 never retry in console mode if the card reports that the port does
 not support DDC (usually this means that the port has no display
 devices connected)

3 files changed, 20 insertions, 10 deletions

diff --git a/NEWS b/NEWS
index cb419ee..ac3af07 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,9 @@
   o add --skip-vbe-check for skipping call for VBE info; useful if
     calling the program multiple times for different ports
   o on failure, return exit status 2 if no successful VBE calls were made
+  o never retry in console mode if the card reports that the port does
+    not support DDC (usually this means that the port has no display
+    devices connected)
 
 - monitor-parse-edid:
   o print EDID version and the number of EDID extension blocks
diff --git a/monitor-get-edid-using-vbe.c b/monitor-get-edid-using-vbe.c
index abd9e9a..0ba76dd 100644
--- a/monitor-get-edid-using-vbe.c
+++ b/monitor-get-edid-using-vbe.c
@@ -37,7 +37,7 @@ int main(int argc, char **argv)
 
   int size = get_edid(edid, port, skip_vbe_check);
 
-  if (size <= 0 && try_in_console) {
+  if (size < 0 && try_in_console) {
     int non_X_console = 1;
     struct vt_stat current;
     int fd = open("/dev/console", O_RDWR);
@@ -57,13 +57,13 @@ int main(int argc, char **argv)
     close(fd);
   }
 
-  if (size > 0) {
+  if (size >= 0) {
 	 write(1, edid, size);
 	 return 0;
   }
 
-  /* return 1 when VBE call was ok but not EDID call;
+  /* returns 1 when VBE call was ok but not EDID call;
    * calling program can then speedup call on other ports with --skip-vbe-check;
    * also, calling program knows no ports work if the VBE call failed */
-  return size < 0 ? 2 : 1;
+  return -size;
 }
diff --git a/vbe.c b/vbe.c
index 57c9ac9..fcd9d7f 100644
--- a/vbe.c
+++ b/vbe.c
@@ -203,10 +203,10 @@ static int vbe_check_ddc_capabilities(int port)
 
   if (!(regs.ebx & 3)) {
     log_err("DDC (0x4f15:00): DDC not supported, not continuing\n", i);
-    return 0;
+    return 1;
   }
 
-  return 1;
+  return 2;
 }
 
 static int vbe_get_edid_info(char *edid, int port, int block)
@@ -260,6 +260,12 @@ static int vbe_get_edid_info(char *edid, int port, int block)
   return 1;
 }
 
+/* return values:
+ * size of edid: success
+ * 0: success but no edid
+ * -1: failure, VBE info call worked
+ * -2: failure, VBE info call didn't work
+ */
 int get_edid(char *edid, int port, int skip_vbe_check)
 {
   int i, extensions;
@@ -275,12 +281,13 @@ int get_edid(char *edid, int port, int skip_vbe_check)
       return -1;
   }
 
-  ok = vbe_check_ddc_capabilities(port) &&
-       vbe_get_edid_info(edid, port, 0);
-
-  if (!ok)
+  ok = vbe_check_ddc_capabilities(port);
+  if (ok == 1) /* success but no DDC */
     return 0;
 
+  if (!ok || !vbe_get_edid_info(edid, port, 0))
+    return -2;
+
   extensions = ((unsigned char*)edid)[126];
   if (extensions > MAX_EXTENSION_COUNT) {
     log_err("EDID: Reported %d extensions, only reading %d\n",