diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/jtag/drivers/cmsis_dap.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/src/jtag/drivers/cmsis_dap.c b/src/jtag/drivers/cmsis_dap.c index b5ceb6c..6ab0875 100644 --- a/src/jtag/drivers/cmsis_dap.c +++ b/src/jtag/drivers/cmsis_dap.c @@ -281,6 +281,21 @@ static void cmsis_dap_close(struct cmsis_dap *dap) } } +static void cmsis_dap_flush_read(struct cmsis_dap *dap) +{ + unsigned int i; + /* Some CMSIS-DAP adapters keep buffered packets over + * USB close/open so we need to flush up to 64 old packets + * to be sure all buffers are empty */ + for (i = 0; i < 64; i++) { + int retval = dap->backend->read(dap, 10); + if (retval == ERROR_TIMEOUT_REACHED) + break; + } + if (i) + LOG_DEBUG("Flushed %u packets", i); +} + /* Send a message and receive the reply */ static int cmsis_dap_xfer(struct cmsis_dap *dap, int txlen) { @@ -313,6 +328,8 @@ static int cmsis_dap_xfer(struct cmsis_dap *dap, int txlen) if (resp[0] != current_cmd) { LOG_ERROR("CMSIS-DAP command mismatch. Sent 0x%" PRIx8 " received 0x%" PRIx8, current_cmd, resp[0]); + + cmsis_dap_flush_read(dap); return ERROR_FAIL; } @@ -885,6 +902,8 @@ static int cmsis_dap_init(void) if (retval != ERROR_OK) return retval; + cmsis_dap_flush_read(cmsis_dap_handle); + retval = cmsis_dap_get_caps_info(); if (retval != ERROR_OK) return retval; |