target: try to reexamine even when polling fails

After intermittent connection failures or target power failures it
might be necessary to try reexamination even when polling fails. This
should make communication with Cortex-A targets more reliable.

This was runtime tested with stlink attached to an stm32l1 and an FTDI JTAG
adapter attached to an stm32f1 target.

Change-Id: I38c4db8124b7f4bbf53ddda53c13273449f49c15
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/2721
Tested-by: jenkins
Reviewed-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Andreas Färber <afaerber@suse.de>

1 files changed, 4 insertions, 6 deletions

diff --git a/src/target/target.c b/src/target/target.c
index 8a7547b8..27f8839f 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -2522,29 +2522,27 @@ static int handle_target(void *priv)
 					target->backoff.times *= 2;
 					target->backoff.times++;
 				}
-				LOG_USER("Polling target %s failed, GDB will be halted. Polling again in %dms",
-						target_name(target),
-						target->backoff.times * polling_interval);
 
 				/* Tell GDB to halt the debugger. This allows the user to
 				 * run monitor commands to handle the situation.
 				 */
 				target_call_event_callbacks(target, TARGET_EVENT_GDB_HALT);
-				return retval;
 			}
-			/* Since we succeeded, we reset backoff count */
 			if (target->backoff.times > 0) {
-				LOG_USER("Polling target %s succeeded again, trying to reexamine", target_name(target));
+				LOG_USER("Polling target %s failed, trying to reexamine", target_name(target));
 				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->examined = true;
+					LOG_USER("Examination failed, GDB will be halted. Polling again in %dms",
+						 target->backoff.times * polling_interval);
 					return retval;
 				}
 			}
 
+			/* Since we succeeded, we reset backoff count */
 			target->backoff.times = 0;
 		}
 	}