adiv5: Recover from bad AP access.

E.g. AP1 on a STM32WLE5 points to a ROM table, but access to the ROM table
via AP1 hangs forever.
- Substantial reduce timeout when wait for a response. Valid access should
  succeed fast.
- Abort AP access to free DP for other accesses
- Don't throw exception, only set dp->fault
- React on higher level

src/remote.c

@@ -144,6 +144,7 @@ void remotePacketProcessSWD(uint8_t i, char *packet)
 		if (i==2) {
 			remote_dp.dp_read = firmware_swdp_read;
 			remote_dp.low_access = firmware_swdp_low_access;
+			remote_dp.abort = firmware_swdp_abort;
 			swdptap_init(&remote_dp);
 			_respond(REMOTE_RESP_OK, 0);
 		} else {
@@ -194,6 +195,7 @@ void remotePacketProcessJTAG(uint8_t i, char *packet)
     case REMOTE_INIT: /* JS = initialise ============================= */
 		remote_dp.dp_read = fw_adiv5_jtagdp_read;
 		remote_dp.low_access = fw_adiv5_jtagdp_low_access;
+		remote_dp.abort = adiv5_jtagdp_abort;
 		jtagtap_init();
 		_respond(REMOTE_RESP_OK, 0);
 		break;

src/target/adiv5.c

@@ -414,16 +414,11 @@ static void adiv5_component_probe(ADIv5_AP_t *ap, uint32_t addr, int recursion,
 	if (addr == 0) /* No rom table on this AP */
 		return;
 	volatile uint32_t cidr;
-	volatile struct exception e;
-	TRY_CATCH (e, EXCEPTION_TIMEOUT) {
-		cidr = adiv5_ap_read_id(ap, addr + CIDR0_OFFSET);
-	}
-	if (e.type) {
-		DEBUG_WARN("CIDR read timeout on AP%d, aborting.\n", num_entry);
-		adiv5_dp_abort(ap->dp, ADIV5_DP_ABORT_DAPABORT);
+	cidr = adiv5_ap_read_id(ap, addr + CIDR0_OFFSET);
+	if (ap->dp->fault) {
+		DEBUG_WARN("CIDR read timeout on AP%d, aborting.\n", ap->apsel);
 		return;
 	}
-
 	if ((cidr & ~CID_CLASS_MASK) != CID_PREAMBLE)
 				return;
 #if defined(ENABLE_DEBUG)
@@ -603,6 +598,15 @@ ADIv5_AP_t *adiv5_new_ap(ADIv5_DP_t *dp, uint8_t apsel)
 
 	if(!tmpap.idr) /* IDR Invalid */
 		return NULL;
+	tmpap.csw = adiv5_ap_read(&tmpap, ADIV5_AP_CSW) &
+		~(ADIV5_AP_CSW_SIZE_MASK | ADIV5_AP_CSW_ADDRINC_MASK);
+
+	if (tmpap.csw & ADIV5_AP_CSW_TRINPROG) {
+		DEBUG_WARN("AP %d: Transaction in progress. AP is not be usable!\n",
+			apsel);
+		return NULL;
+	}
+
 	/* It's valid to so create a heap copy */
 	ap = malloc(sizeof(*ap));
 	if (!ap) {			/* malloc failed: heap exhaustion */
@@ -612,14 +616,6 @@ ADIv5_AP_t *adiv5_new_ap(ADIv5_DP_t *dp, uint8_t apsel)
 
 	memcpy(ap, &tmpap, sizeof(*ap));
 
-	ap->csw = adiv5_ap_read(ap, ADIV5_AP_CSW) &
-		~(ADIV5_AP_CSW_SIZE_MASK | ADIV5_AP_CSW_ADDRINC_MASK);
-
-	if (ap->csw & ADIV5_AP_CSW_TRINPROG) {
-		DEBUG_WARN("AP transaction in progress.  Target may not be usable.\n");
-		ap->csw &= ~ADIV5_AP_CSW_TRINPROG;
-	}
-
 #if defined(ENABLE_DEBUG)
 	uint32_t cfg = adiv5_ap_read(ap, ADIV5_AP_CFG);
 	DEBUG_INFO("AP %3d: IDR=%08"PRIx32" CFG=%08"PRIx32" BASE=%08" PRIx32

src/target/adiv5.h

@@ -310,4 +310,5 @@ uint32_t fw_adiv5_jtagdp_read(ADIv5_DP_t *dp, uint16_t addr);
 uint32_t firmware_swdp_error(ADIv5_DP_t *dp);
 
 void firmware_swdp_abort(ADIv5_DP_t *dp, uint32_t abort);
+void adiv5_jtagdp_abort(ADIv5_DP_t *dp, uint32_t abort);
 #endif

src/target/adiv5_jtagdp.c

@@ -39,8 +39,6 @@
 
 static uint32_t adiv5_jtagdp_error(ADIv5_DP_t *dp);
 
-static void adiv5_jtagdp_abort(ADIv5_DP_t *dp, uint32_t abort);
-
 void adiv5_jtag_dp_handler(uint8_t jd_index, uint32_t j_idcode)
 {
 	ADIv5_DP_t *dp = (void*)calloc(1, sizeof(*dp));
@@ -87,23 +85,25 @@ uint32_t fw_adiv5_jtagdp_low_access(ADIv5_DP_t *dp, uint8_t RnW,
 
 	jtag_dev_write_ir(&jtag_proc, dp->dp_jd_index, APnDP ? IR_APACC : IR_DPACC);
 
-	platform_timeout_set(&timeout, 2000);
+	platform_timeout_set(&timeout, 20);
 	do {
 		jtag_dev_shift_dr(&jtag_proc, dp->dp_jd_index, (uint8_t*)&response,
 						  (uint8_t*)&request, 35);
 		ack = response & 0x07;
 	} while(!platform_timeout_is_expired(&timeout) && (ack == JTAGDP_ACK_WAIT));
 
-	if (ack == JTAGDP_ACK_WAIT)
-		raise_exception(EXCEPTION_TIMEOUT, "JTAG-DP ACK timeout");
-
+	if (ack == JTAGDP_ACK_WAIT) {
+		dp->abort(dp, ADIV5_DP_ABORT_DAPABORT);
+		dp->fault = 1;
+		return 0;
+	}
 	if((ack != JTAGDP_ACK_OK))
 		raise_exception(EXCEPTION_ERROR, "JTAG-DP invalid ACK");
 
 	return (uint32_t)(response >> 3);
 }
 
-static void adiv5_jtagdp_abort(ADIv5_DP_t *dp, uint32_t abort)
+void adiv5_jtagdp_abort(ADIv5_DP_t *dp, uint32_t abort)
 {
 	uint64_t request = (uint64_t)abort << 3;
 	jtag_dev_write_ir(&jtag_proc, dp->dp_jd_index, IR_ABORT);

src/target/adiv5_swdp.c

@@ -93,6 +93,8 @@ int adiv5_swdp_scan(uint32_t targetid)
 		initial_dp->error = firmware_swdp_error;
 	if (!initial_dp->low_access)
        initial_dp->low_access = firmware_swdp_low_access;
+	if (!initial_dp->abort)
+       initial_dp->abort = firmware_swdp_abort;
 	/* DORMANT-> SWD sequence*/
 	initial_dp->seq_out(0xFFFFFFFF, 32);
 	initial_dp->seq_out(0xFFFFFFFF, 32);
@@ -241,7 +243,7 @@ uint32_t firmware_swdp_low_access(ADIv5_DP_t *dp, uint8_t RnW,
 
 	if((addr & ADIV5_APnDP) && dp->fault) return 0;
 
-	platform_timeout_set(&timeout, 2000);
+	platform_timeout_set(&timeout, 20);
 	do {
 		dp->seq_out(request, 8);
 		ack = dp->seq_in(3);
@@ -251,8 +253,11 @@ uint32_t firmware_swdp_low_access(ADIv5_DP_t *dp, uint8_t RnW,
 		}
 	} while (ack == SWDP_ACK_WAIT && !platform_timeout_is_expired(&timeout));
 
-	if (ack == SWDP_ACK_WAIT)
-		raise_exception(EXCEPTION_TIMEOUT, "SWDP ACK timeout");
+	if (ack == SWDP_ACK_WAIT) {
+		dp->abort(dp, ADIV5_DP_ABORT_DAPABORT);
+		dp->fault = 1;
+		return 0;
+	}
 
 	if(ack == SWDP_ACK_FAULT) {
 		dp->fault = 1;