From 9fce8a21ca5f7f42ec36aa859637d37f5fba312a Mon Sep 17 00:00:00 2001 From: Angus Gratton Date: Sat, 28 Jun 2014 09:27:11 +1000 Subject: [PATCH] stlink_usb: Fix swallowed error on read/write operations, add retries on SWD WAIT, clean up error debug output. - stlink_usb_get_rw_status() had a bug where FAULT or WAIT responses in read/write operations were ignored, leading to incomplete data. - Added wrapper stlink_cmd_allow_retry to handle SWD_AP_WAIT/SWD_DP_WAIT statuses in most commands. These statuses appear if an SWD read or write received a WAIT ACK response from the target more than 4 times in a row. The driver retries the operation (with exponential backoff) before failing outright (in testing 1 retry was always enough.) - As part of the implementation of stlink_cmd_allow_retry a large number of lines of boilerplate were refactored. - Fleshed out stlink_usb_error_check and added it to some more code paths so WAIT or FAULT responses are logged to debug. WAIT responses will be logged even if they are subsequently retried, which should help in case the retries have subtle side effects (none anticipated.) Tested with two targets: STLINK F0 Discovery, Nordic NRF51822. Only tested with STLINK V2 programmers. Change-Id: I9af24e8f0121b035356dbb9978d6bbf4feb2e4d3 Signed-off-by: Angus Gratton Reviewed-on: http://openocd.zylin.com/2201 Tested-by: jenkins Reviewed-by: Andreas Fritiofson --- src/helper/log.h | 2 + src/jtag/drivers/stlink_usb.c | 213 ++++++++++++++++------------------ 2 files changed, 104 insertions(+), 111 deletions(-) diff --git a/src/helper/log.h b/src/helper/log.h index e1801e9fb5..7f9f32c59a 100644 --- a/src/helper/log.h +++ b/src/helper/log.h @@ -138,5 +138,7 @@ extern int debug_level; * make no assumptions about what went wrong and try to handle the problem. */ #define ERROR_FAIL (-4) +#define ERROR_WAIT (-5) + #endif /* LOG_H */ diff --git a/src/jtag/drivers/stlink_usb.c b/src/jtag/drivers/stlink_usb.c index fd5f2834c0..77448d5082 100644 --- a/src/jtag/drivers/stlink_usb.c +++ b/src/jtag/drivers/stlink_usb.c @@ -66,6 +66,11 @@ * 8bit read/writes to max 64 bytes. */ #define STLINK_MAX_RW8 (64) +/* "WAIT" responses will be retried (with exponential backoff) at + * most this many times before failing to caller. + */ +#define MAX_WAIT_RETRIES 8 + enum stlink_jtag_api_version { STLINK_JTAG_API_V1 = 1, STLINK_JTAG_API_V2, @@ -343,6 +348,64 @@ static int stlink_usb_xfer(void *handle, const uint8_t *buf, int size) return ERROR_OK; } + +/** + Converts an STLINK status code held in the first byte of a response + to an openocd error, logs any error/wait status as debug output. +*/ +static int stlink_usb_error_check(void *handle) +{ + struct stlink_usb_handle_s *h = handle; + + assert(handle != NULL); + + /* TODO: no error checking yet on api V1 */ + if (h->jtag_api == STLINK_JTAG_API_V1) + h->databuf[0] = STLINK_DEBUG_ERR_OK; + + switch (h->databuf[0]) { + case STLINK_DEBUG_ERR_OK: + return ERROR_OK; + case STLINK_DEBUG_ERR_FAULT: + LOG_DEBUG("SWD fault response (0x%x)", STLINK_DEBUG_ERR_FAULT); + return ERROR_FAIL; + case STLINK_SWD_AP_WAIT: + LOG_DEBUG("wait status SWD_AP_WAIT (0x%x)", STLINK_SWD_AP_WAIT); + return ERROR_WAIT; + case STLINK_SWD_DP_WAIT: + LOG_DEBUG("wait status SWD_DP_WAIT (0x%x)", STLINK_SWD_AP_WAIT); + return ERROR_WAIT; + default: + LOG_DEBUG("unknown/unexpected STLINK status code 0x%x", h->databuf[0]); + return ERROR_FAIL; + } +} + + +/** Issue an STLINK command via USB transfer, with retries on any wait status responses. + + Works for commands where the STLINK_DEBUG status is returned in the first + byte of the response packet. + + Returns an openocd result code. +*/ +static int stlink_cmd_allow_retry(void *handle, const uint8_t *buf, int size) +{ + int retries = 0; + int res; + while (1) { + res = stlink_usb_xfer(handle, buf, size); + if (res != ERROR_OK) + return res; + res = stlink_usb_error_check(handle); + if (res == ERROR_WAIT && retries < MAX_WAIT_RETRIES) { + usleep((1<jtag_api == STLINK_JTAG_API_V1) - h->databuf[0] = STLINK_DEBUG_ERR_OK; - - switch (h->databuf[0]) { - case STLINK_DEBUG_ERR_OK: - res = ERROR_OK; - break; - case STLINK_DEBUG_ERR_FAULT: - default: - err_msg = stlink_usb_error_msg[0]; - res = ERROR_FAIL; - break; - } - - if (res != ERROR_OK) - LOG_DEBUG("status error: %d ('%s')", h->databuf[0], err_msg); - - return res; -} - /** */ static int stlink_usb_version(void *handle) { @@ -530,7 +559,6 @@ static int stlink_usb_current_mode(void *handle, uint8_t *mode) /** */ static int stlink_usb_mode_enter(void *handle, enum stlink_mode type) { - int res; int rx_size = 0; struct stlink_usb_handle_s *h = handle; @@ -572,14 +600,7 @@ static int stlink_usb_mode_enter(void *handle, enum stlink_mode type) return ERROR_FAIL; } - res = stlink_usb_xfer(handle, h->databuf, rx_size); - - if (res != ERROR_OK) - return res; - - res = stlink_usb_error_check(h); - - return res; + return stlink_cmd_allow_retry(handle, h->databuf, rx_size); } /** */ @@ -775,19 +796,16 @@ static int stlink_usb_v2_read_debug_reg(void *handle, uint32_t addr, uint32_t *v h_u32_to_le(h->cmdbuf+h->cmdidx, addr); h->cmdidx += 4; - res = stlink_usb_xfer(handle, h->databuf, 8); - + res = stlink_cmd_allow_retry(handle, h->databuf, 8); if (res != ERROR_OK) return res; *val = le_to_h_u32(h->databuf + 4); - - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return ERROR_OK; } static int stlink_usb_write_debug_reg(void *handle, uint32_t addr, uint32_t val) { - int res; struct stlink_usb_handle_s *h = handle; assert(handle != NULL); @@ -804,12 +822,7 @@ static int stlink_usb_write_debug_reg(void *handle, uint32_t addr, uint32_t val) h_u32_to_le(h->cmdbuf+h->cmdidx, val); h->cmdidx += 4; - res = stlink_usb_xfer(handle, h->databuf, 2); - - if (res != ERROR_OK) - return res; - - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return stlink_cmd_allow_retry(handle, h->databuf, 2); } /** */ @@ -921,7 +934,6 @@ static enum target_state stlink_usb_state(void *handle) /** */ static int stlink_usb_reset(void *handle) { - int res; struct stlink_usb_handle_s *h = handle; assert(handle != NULL); @@ -935,23 +947,11 @@ static int stlink_usb_reset(void *handle) else h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_RESETSYS; - res = stlink_usb_xfer(handle, h->databuf, 2); - - if (res != ERROR_OK) - return res; - - LOG_DEBUG("RESET: 0x%08X", h->databuf[0]); - - /* the following is not a error under swd (using hardware srst), so return success */ - if (h->databuf[0] == STLINK_SWD_AP_WAIT || h->databuf[0] == STLINK_SWD_DP_WAIT) - return ERROR_OK; - - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return stlink_cmd_allow_retry(handle, h->databuf, 2); } static int stlink_usb_assert_srst(void *handle, int srst) { - int res; struct stlink_usb_handle_s *h = handle; assert(handle != NULL); @@ -965,12 +965,7 @@ static int stlink_usb_assert_srst(void *handle, int srst) h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_DRIVE_NRST; h->cmdbuf[h->cmdidx++] = srst; - res = stlink_usb_xfer(handle, h->databuf, 2); - - if (res != ERROR_OK) - return res; - - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return stlink_cmd_allow_retry(handle, h->databuf, 2); } /** */ @@ -1130,12 +1125,7 @@ static int stlink_usb_run(void *handle) h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND; h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_RUNCORE; - res = stlink_usb_xfer(handle, h->databuf, 2); - - if (res != ERROR_OK) - return res; - - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return stlink_cmd_allow_retry(handle, h->databuf, 2); } /** */ @@ -1160,18 +1150,12 @@ static int stlink_usb_halt(void *handle) h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND; h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_FORCEDEBUG; - res = stlink_usb_xfer(handle, h->databuf, 2); - - if (res != ERROR_OK) - return res; - - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return stlink_cmd_allow_retry(handle, h->databuf, 2); } /** */ static int stlink_usb_step(void *handle) { - int res; struct stlink_usb_handle_s *h = handle; assert(handle != NULL); @@ -1189,12 +1173,7 @@ static int stlink_usb_step(void *handle) h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND; h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_STEPCORE; - res = stlink_usb_xfer(handle, h->databuf, 2); - - if (res != ERROR_OK) - return res; - - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return stlink_cmd_allow_retry(handle, h->databuf, 2); } /** */ @@ -1238,25 +1217,24 @@ static int stlink_usb_read_reg(void *handle, int num, uint32_t *val) h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READREG; h->cmdbuf[h->cmdidx++] = num; - res = stlink_usb_xfer(handle, h->databuf, h->jtag_api == STLINK_JTAG_API_V1 ? 4 : 8); - - if (res != ERROR_OK) - return res; - - if (h->jtag_api == STLINK_JTAG_API_V1) + if (h->jtag_api == STLINK_JTAG_API_V1) { + res = stlink_usb_xfer(handle, h->databuf, 4); + if (res != ERROR_OK) + return res; *val = le_to_h_u32(h->databuf); - else { + return ERROR_OK; + } else { + res = stlink_cmd_allow_retry(handle, h->databuf, 8); + if (res != ERROR_OK) + return res; *val = le_to_h_u32(h->databuf + 4); - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return ERROR_OK; } - - return ERROR_OK; } /** */ static int stlink_usb_write_reg(void *handle, int num, uint32_t val) { - int res; struct stlink_usb_handle_s *h = handle; assert(handle != NULL); @@ -1272,12 +1250,7 @@ static int stlink_usb_write_reg(void *handle, int num, uint32_t val) h_u32_to_le(h->cmdbuf+h->cmdidx, val); h->cmdidx += 4; - res = stlink_usb_xfer(handle, h->databuf, 2); - - if (res != ERROR_OK) - return res; - - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL; + return stlink_cmd_allow_retry(handle, h->databuf, 2); } static int stlink_usb_get_rw_status(void *handle) @@ -1300,7 +1273,7 @@ static int stlink_usb_get_rw_status(void *handle) if (res != ERROR_OK) return res; - return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : res; + return stlink_usb_error_check(h); } /** */ @@ -1453,6 +1426,7 @@ static int stlink_usb_read_mem(void *handle, uint32_t addr, uint32_t size, { int retval = ERROR_OK; uint32_t bytes_remaining; + int retries = 0; struct stlink_usb_handle_s *h = handle; /* calculate byte count */ @@ -1483,6 +1457,10 @@ static int stlink_usb_read_mem(void *handle, uint32_t addr, uint32_t size, uint32_t head_bytes = 4 - (addr % 4); retval = stlink_usb_read_mem8(handle, addr, head_bytes, buffer); + if (retval == ERROR_WAIT && retries < MAX_WAIT_RETRIES) { + usleep((1<