monitor-get-edid-using-vbe:

add basic 15 sec timeout, with --no-timeout for disabling it

2 files changed, 18 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index 505c945..e777147 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@
   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)
+  o add basic 15 sec timeout, with --no-timeout for disabling it
 
 - 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 0ba76dd..f922a6b 100644
--- a/monitor-get-edid-using-vbe.c
+++ b/monitor-get-edid-using-vbe.c
@@ -7,18 +7,27 @@
 #include <fcntl.h>
 #include <errno.h>
 #include <stdarg.h>
+#include <signal.h>
 #include <sys/ioctl.h>
 #include <sys/vt.h>
 #include "get-edid.h"
 
 int verbose = 0;
 
+static void timeout_handler(int signal)
+{
+  fprintf(stderr, "ERROR: timeout during EDID probe\n");
+  exit(1);
+}
+
 int main(int argc, char **argv)
 {
+  struct sigaction timeout_action;
   char edid[(1 + MAX_EXTENSION_COUNT) * EDID_BLOCK_SIZE];
   int try_in_console = 0;
   int skip_vbe_check = 0;
   int port = 0;
+  int no_timeout = 0;
   int i;
 
   for (i = 1; i < argc; i++) {
@@ -27,14 +36,21 @@ int main(int argc, char **argv)
     else if (strcmp(arg, "--port") == 0 && i+1 < argc) port = atoi(argv[++i]);
     else if (strcmp(arg, "--try-in-console") == 0) try_in_console = 1;
     else if (strcmp(arg, "--skip-vbe-check") == 0) skip_vbe_check = 1;
+    else if (strcmp(arg, "--no-timeout") == 0) no_timeout = 1;
     else if (strcmp(arg, "-h") == 0 ||
 	     strcmp(arg, "--help") == 0) {
       printf("usage: monitor-get-edid [-v] [--port <0-3>] [--try-in-console]\n"
-	     "                        [--skip-vbe-check]\n");
+	     "                        [--skip-vbe-check] [--no-timeout]\n");
       exit(1);
     }
   }
 
+  if (!no_timeout) {
+    timeout_action.sa_handler = timeout_handler;
+    sigaction(SIGALRM, &timeout_action, NULL);
+    alarm(15);
+  }
+
   int size = get_edid(edid, port, skip_vbe_check);
 
   if (size < 0 && try_in_console) {