diff --git a/src/target/target.c b/src/target/target.c index f178ae368..d7607e3a4 100644 --- a/src/target/target.c +++ b/src/target/target.c @@ -96,6 +96,7 @@ static struct target_type *target_types[] = struct target *all_targets = NULL; static struct target_event_callback *target_event_callbacks = NULL; static struct target_timer_callback *target_timer_callbacks = NULL; +static const int polling_interval = 100; static const Jim_Nvp nvp_assert[] = { { .name = "assert", NVP_ASSERT }, @@ -862,7 +863,7 @@ static int target_init(struct command_context *cmd_ctx) return retval; retval = target_register_timer_callback(&handle_target, - 100, 1, cmd_ctx->interp); + polling_interval, 1, cmd_ctx->interp); if (ERROR_OK != retval) return retval; @@ -1800,6 +1801,9 @@ static int sense_handler(void) return ERROR_OK; } +static int backoff_times = 0; +static int backoff_count = 0; + /* process target state changes */ static int handle_target(void *priv) { @@ -1862,6 +1866,14 @@ static int handle_target(void *priv) recursive = 0; } + if (backoff_times > backoff_count) + { + /* do not poll this time as we failed previously */ + backoff_count++; + return ERROR_OK; + } + backoff_count = 0; + /* Poll targets for state changes unless that's globally disabled. * Skip targets that are currently disabled. */ @@ -1878,17 +1890,26 @@ static int handle_target(void *priv) /* polling may fail silently until the target has been examined */ if ((retval = target_poll(target)) != ERROR_OK) { - /* FIX!!!!! If we add a LOG_INFO() here to output a line in GDB - * *why* we are aborting GDB, then we'll spam telnet when the - * poll is failing persistently. - * - * If we could implement an event that detected the - * target going from non-pollable to pollable, we could issue - * an error only upon the transition. + /* 100ms polling interval. Increase interval between polling up to 5000ms */ + if (backoff_times * polling_interval < 5000) + { + backoff_times *= 2; + backoff_times++; + } + LOG_USER("Polling target failed, GDB will be halted. Polling again in %dms", 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 (backoff_times > 0) + { + LOG_USER("Polling succeeded again"); + } + backoff_times = 0; } }