target/arm_adi_v5, cortex_m: retry ahbap_debugport_init few times in case of an error

Some targets need arbitrary amount of time (usually not too long)
after reset (both sysresetreq and srst) to do initialisation, and
SWD/JTAG is not available during that. According to PSoC4 docs, the
debugger should try connecting until it succeeds.

Also ahbap_debugport_init might be necessary to perform after using
hardware srst too, so add it there (except for the targets that
support srst_nogate since they are very unlikely to need it).

Change-Id: I3598d5ff7b8e0bf3a5566a57dec4b0b2b243d297
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/2601
Tested-by: jenkins

diff --git a/src/target/arm_adi_v5.c b/src/target/arm_adi_v5.c
index 4f19e954867828341b177caa97ec0e14f2f7319f..3df39f9edb2908ef27dd6e7415ffdd989b503822 100644 (file)
--- a/src/target/arm_adi_v5.c
+++ b/src/target/arm_adi_v5.c
@@ -642,6 +642,8 @@ extern const struct dap_ops jtag_dp_ops;
  */
 int ahbap_debugport_init(struct adiv5_dap *dap)
 {
+       /* check that we support packed transfers */
+       uint32_t csw, cfg;
        int retval;
 
        LOG_DEBUG(" ");
@@ -663,70 +665,74 @@ int ahbap_debugport_init(struct adiv5_dap *dap)
        dap_ap_select(dap, 0);
        dap->last_read = NULL;
 
-       /* DP initialization */
+       for (size_t i = 0; i < 10; i++) {
+               /* DP initialization */
 
-       dap->dp_bank_value = 0;
+               dap->dp_bank_value = 0;
 
-       retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
-       if (retval != ERROR_OK)
-               return retval;
+               retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
+               if (retval != ERROR_OK)
+                       continue;
 
-       retval = dap_queue_dp_write(dap, DP_CTRL_STAT, SSTICKYERR);
-       if (retval != ERROR_OK)
-               return retval;
+               retval = dap_queue_dp_write(dap, DP_CTRL_STAT, SSTICKYERR);
+               if (retval != ERROR_OK)
+                       continue;
 
-       retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
-       if (retval != ERROR_OK)
-               return retval;
+               retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
+               if (retval != ERROR_OK)
+                       continue;
 
-       dap->dp_ctrl_stat = CDBGPWRUPREQ | CSYSPWRUPREQ;
-       retval = dap_queue_dp_write(dap, DP_CTRL_STAT, dap->dp_ctrl_stat);
-       if (retval != ERROR_OK)
-               return retval;
+               dap->dp_ctrl_stat = CDBGPWRUPREQ | CSYSPWRUPREQ;
+               retval = dap_queue_dp_write(dap, DP_CTRL_STAT, dap->dp_ctrl_stat);
+               if (retval != ERROR_OK)
+                       continue;
 
-       /* Check that we have debug power domains activated */
-       LOG_DEBUG("DAP: wait CDBGPWRUPACK");
-       retval = dap_dp_poll_register(dap, DP_CTRL_STAT,
-                                     CDBGPWRUPACK, CDBGPWRUPACK,
-                                     DAP_POWER_DOMAIN_TIMEOUT);
-       if (retval != ERROR_OK)
-               return retval;
+               /* Check that we have debug power domains activated */
+               LOG_DEBUG("DAP: wait CDBGPWRUPACK");
+               retval = dap_dp_poll_register(dap, DP_CTRL_STAT,
+                                             CDBGPWRUPACK, CDBGPWRUPACK,
+                                             DAP_POWER_DOMAIN_TIMEOUT);
+               if (retval != ERROR_OK)
+                       continue;
 
-       LOG_DEBUG("DAP: wait CSYSPWRUPACK");
-       retval = dap_dp_poll_register(dap, DP_CTRL_STAT,
-                                     CSYSPWRUPACK, CSYSPWRUPACK,
-                                     DAP_POWER_DOMAIN_TIMEOUT);
-       if (retval != ERROR_OK)
-               return retval;
+               LOG_DEBUG("DAP: wait CSYSPWRUPACK");
+               retval = dap_dp_poll_register(dap, DP_CTRL_STAT,
+                                             CSYSPWRUPACK, CSYSPWRUPACK,
+                                             DAP_POWER_DOMAIN_TIMEOUT);
+               if (retval != ERROR_OK)
+                       continue;
 
-       retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
-       if (retval != ERROR_OK)
-               return retval;
-       /* With debug power on we can activate OVERRUN checking */
-       dap->dp_ctrl_stat = CDBGPWRUPREQ | CSYSPWRUPREQ | CORUNDETECT;
-       retval = dap_queue_dp_write(dap, DP_CTRL_STAT, dap->dp_ctrl_stat);
-       if (retval != ERROR_OK)
-               return retval;
-       retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
-       if (retval != ERROR_OK)
-               return retval;
+               retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
+               if (retval != ERROR_OK)
+                       continue;
+               /* With debug power on we can activate OVERRUN checking */
+               dap->dp_ctrl_stat = CDBGPWRUPREQ | CSYSPWRUPREQ | CORUNDETECT;
+               retval = dap_queue_dp_write(dap, DP_CTRL_STAT, dap->dp_ctrl_stat);
+               if (retval != ERROR_OK)
+                       continue;
+               retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
+               if (retval != ERROR_OK)
+                       continue;
 
-       /* check that we support packed transfers */
-       uint32_t csw, cfg;
+               retval = dap_setup_accessport(dap, CSW_8BIT | CSW_ADDRINC_PACKED, 0);
+               if (retval != ERROR_OK)
+                       continue;
 
-       retval = dap_setup_accessport(dap, CSW_8BIT | CSW_ADDRINC_PACKED, 0);
-       if (retval != ERROR_OK)
-               return retval;
+               retval = dap_queue_ap_read(dap, AP_REG_CSW, &csw);
+               if (retval != ERROR_OK)
+                       continue;
 
-       retval = dap_queue_ap_read(dap, AP_REG_CSW, &csw);
-       if (retval != ERROR_OK)
-               return retval;
+               retval = dap_queue_ap_read(dap, AP_REG_CFG, &cfg);
+               if (retval != ERROR_OK)
+                       continue;
 
-       retval = dap_queue_ap_read(dap, AP_REG_CFG, &cfg);
-       if (retval != ERROR_OK)
-               return retval;
+               retval = dap_run(dap);
+               if (retval != ERROR_OK)
+                       continue;
+
+               break;
+       }
 
-       retval = dap_run(dap);
        if (retval != ERROR_OK)
                return retval;
 

diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c
index 3e42af0a3d864ea4faeac75024368ae02d48d190..2cb83a496fe85bb94d419bd35bf70d27cb35bfd6 100644 (file)
--- a/src/target/cortex_m.c
+++ b/src/target/cortex_m.c
@@ -1107,6 +1107,17 @@ static int cortex_m_deassert_reset(struct target *target)
        /* deassert reset lines */
        adapter_deassert_reset();
 
+       enum reset_types jtag_reset_config = jtag_get_reset_config();
+
+       if ((jtag_reset_config & RESET_HAS_SRST) &&
+           !(jtag_reset_config & RESET_SRST_NO_GATING)) {
+               int retval = ahbap_debugport_init(target_to_cm(target)->armv7m.arm.dap);
+               if (retval != ERROR_OK) {
+                       LOG_ERROR("DP initialisation failed");
+                       return retval;
+               }
+       }
+
        return ERROR_OK;
 }