target: introduce active_polled flag in struct target

The spliting of examined status to two partialy independent flags
resolves the dirty hack of setting examined after failed examine call
in handle_target() and ambiguity in the examined flag usage.

Change-Id: I16567248f81d6b096d864ef11480e6c611398494
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/9180
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

Author: tom-van

src/target/target.c

@@ -658,13 +658,17 @@ static int no_mmu(struct target *target, bool *enabled)
 
 /**
  * Reset the @c examined flag for the given target.
- * Pure paranoia -- targets are zeroed on allocation.
  */
 static inline void target_reset_examined(struct target *target)
 {
 	target->examined = false;
 }
 
+static inline void target_reset_active_polled(struct target *target)
+{
+	target->active_polled = false;
+}
+
 static int default_examine(struct target *target)
 {
 	target_set_examined(target);
@@ -1495,6 +1499,7 @@ static int target_init_one(struct command_context *cmd_ctx,
 		struct target *target)
 {
 	target_reset_examined(target);
+	target_reset_active_polled(target);
 
 	struct target_type *type = target->type;
 	if (!type->examine)
@@ -2922,7 +2927,7 @@ static int handle_target(void *priv)
 			is_jtag_poll_safe() && target;
 			target = target->next) {
 
-		if (!target_was_examined(target))
+		if (!target_active_polled(target))
 			continue;
 
 		if (!target->tap->enabled)
@@ -2955,10 +2960,7 @@ static int handle_target(void *priv)
 				LOG_TARGET_ERROR(target, "Polling failed, trying to reexamine");
 				target_reset_examined(target);
 				retval = target_examine_one(target);
-				/* Target examination could have failed due to unstable connection,
-				 * but we set the examined flag anyway to repoll it later */
 				if (retval != ERROR_OK) {
-					target_set_examined(target);
 					LOG_TARGET_ERROR(target, "Examination failed, GDB will be halted. Polling again in %dms",
 						 target->backoff.times * polling_interval);
 					return retval;
@@ -5349,8 +5351,10 @@ COMMAND_HANDLER(handle_target_reset)
 	/* do the assert */
 	if (n->value == NVP_ASSERT) {
 		int retval = target->type->assert_reset(target);
-		if (target->defer_examine)
+		if (target->defer_examine) {
 			target_reset_examined(target);
+			target_reset_active_polled(target);
+		}
 		return retval;
 	}
 

src/target/target.h

@@ -126,12 +126,19 @@ struct target {
 	bool defer_examine;
 
 	/**
-	 * Indicates whether this target has been examined.
+	 * Indicates whether this target has been examined,
+	 * remembers the last result of examine call.
 	 *
 	 * Do @b not access this field directly, use target_was_examined()
 	 * or target_set_examined().
 	 */
 	bool examined;
+	/**
+	 * The flag is set after a successful examine call.
+	 * It remains set forever or in the case of defer examine
+	 * gets reset by reset command.
+	 */
+	bool active_polled;
 
 	/**
 	 * true if the  target is currently running a downloaded
@@ -428,16 +435,26 @@ const char *target_type_name(const struct target *target);
  */
 int target_examine_one(struct target *target);
 
-/** @returns @c true if target_set_examined() has been called. */
+/** @returns @c true if target_set_examined() has been called.
+ *  The returned value reflects the last examination result. */
 static inline bool target_was_examined(const struct target *target)
 {
 	return target->examined;
 }
 
-/** Sets the @c examined flag for the given target. */
+/** @returns @c true if target_set_examined() has been called.
+ *  The flag remains set forever or in the case of defer examine
+ *  gets reset by reset command */
+static inline bool target_active_polled(const struct target *target)
+{
+	return target->active_polled;
+}
+
+/** Sets the @c examined and @c active_polled flags for the given target. */
 /** Use in target->type->examine() after one-time setup is done. */
 static inline void target_set_examined(struct target *target)
 {
+	target->active_polled = true;
 	target->examined = true;
 }