lib/igt_aux: Improve wait_for_keypress helper a bit

- Use keys in just one env variable to enable/disable it.
- Add an informational message so that the users knows when to press
  the key (more useful over ssh than when run on the terminal ofc).
- Improve the documentation so that it's clearer how to use this
  when running tests.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Acked-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

lib/igt_aux.c

@@ -344,21 +344,37 @@ void igt_drop_root(void)
 }
 
 /**
- * igt_wait_for_keypress:
+ * igt_debug_wait_for_keypress:
+ * @key: env var lookup to to enable this wait
  *
- * Waits for a key press when run interactively. When not connected to a
+ * Waits for a key press when run interactively and when the corresponding debug
- * terminal immediately continues.
+ * key is set in the IGT_DEBUG_INTERACTIVE environment variable. Multiple keys
+ * can be specified as a comma-separated list or alternatively "all" if a wait
+ * should happen for all keys.  When not connected to a terminal the enviroment
+ * setting is ignored and execution immediately continues.
  *
  * This is useful for display tests where under certain situation manual
- * inspection of the display is useful.
+ * inspection of the display is useful. Or when running a testcase in the
+ * background.
  */
-void igt_wait_for_keypress(void)
+void igt_debug_wait_for_keypress(const char *key)
 {
 	struct termios oldt, newt;
+	const char *env;
 
 	if (!isatty(STDIN_FILENO))
 		return;
 
+	env = getenv("IGT_DEBUG_INTERACTIVE");
+
+	if (!env)
+		return;
+
+	if (!strstr(env, key) && !strstr(env, "all"))
+		return;
+
+	igt_info("Press any key to continue ...\n");
+
 	tcgetattr ( STDIN_FILENO, &oldt );
 	newt = oldt;
 	newt.c_lflag &= ~( ICANON | ECHO );

lib/igt_aux.h

@@ -56,7 +56,7 @@ void igt_system_suspend_autoresume(void);
 /* dropping priviledges */
 void igt_drop_root(void);
 
-void igt_wait_for_keypress(void);
+void igt_debug_wait_for_keypress(const char *key);
 
 enum igt_runtime_pm_status {
 	IGT_RUNTIME_PM_STATUS_ACTIVE,

lib/igt_kms.c

@@ -1401,8 +1401,7 @@ static int do_display_commit(igt_display_t *display,
 
 	LOG_UNINDENT(display);
 
-	if (getenv("IGT_DISPLAY_WAIT_AT_COMMIT"))
+	igt_debug_wait_for_keypress("modeset");
-		igt_wait_for_keypress();
 
 	return 0;
 }