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jtag/drivers/bitbang: limit SWD WAIT retries by timeout 

The bitbang driver kept retrying a SWD command as long as
the debugged device had been responding by SWD WAIT.
If the DP stalled in WAIT permanently, OpenOCD hanged.

Check 0.5 sec timeout in WAIT retry loop.

While on it insert a short alive_sleep() if the command
is retried 20 or more times.

Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Change-Id: I744e56e21a5a2dc2c4494cc0d7bbcb4be14ddb23
Reviewed-on: https://review.openocd.org/c/openocd/+/8153
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: jenkins
This commit is contained in:
Tomas Vanek 2024-02-17 13:14:01 +01:00 committed by Antonio Borneo
parent f7f4fa84f1
commit 31af18e9d1
1 changed files with 16 additions and 2 deletions
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18
src/jtag/drivers/bitbang.c
View File

@ -20,6 +20,11 @@
#include <jtag/interface.h>
#include <jtag/commands.h>
#include <helper/time_support.h>
/* Timeout for retrying on SWD WAIT in msec */
#define SWD_WAIT_TIMEOUT 500
/**
* Function bitbang_stableclocks
* issues a number of clock cycles while staying in a stable state.
@ -474,6 +479,7 @@ static void bitbang_swd_read_reg(uint8_t cmd, uint32_t *value, uint32_t ap_delay
return;
}
int64_t timeout = timeval_ms() + SWD_WAIT_TIMEOUT;
for (unsigned int retry = 0;; retry++) {
uint8_t trn_ack_data_parity_trn[DIV_ROUND_UP(4 + 3 + 32 + 1 + 4, 8)];
@ -496,8 +502,11 @@ static void bitbang_swd_read_reg(uint8_t cmd, uint32_t *value, uint32_t ap_delay
(cmd & SWD_CMD_A32) >> 1,
data);
if (ack == SWD_ACK_WAIT) {
if (ack == SWD_ACK_WAIT && timeval_ms() <= timeout) {
swd_clear_sticky_errors();
if (retry > 20)
alive_sleep(1);
continue;
}
if (retry > 1)
@ -530,6 +539,8 @@ static void bitbang_swd_write_reg(uint8_t cmd, uint32_t value, uint32_t ap_delay
return;
}
int64_t timeout = timeval_ms() + SWD_WAIT_TIMEOUT;
/* Devices do not reply to DP_TARGETSEL write cmd, ignore received ack */
bool check_ack = swd_cmd_returns_ack(cmd);
@ -569,8 +580,11 @@ static void bitbang_swd_write_reg(uint8_t cmd, uint32_t value, uint32_t ap_delay
(cmd & SWD_CMD_A32) >> 1,
buf_get_u32(trn_ack_data_parity_trn, 1 + 3 + 1, 32));
if (check_ack && ack == SWD_ACK_WAIT) {
if (check_ack && ack == SWD_ACK_WAIT && timeval_ms() <= timeout) {
swd_clear_sticky_errors();
if (retry > 20)
alive_sleep(1);
continue;
}