diff --git a/doc/openocd.texi b/doc/openocd.texi
index fd92d51acfcca70ac993859f1e866cdc9032b378..892661fd4a48dd0cf8952405300842634c33ea46 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -6720,21 +6720,8 @@ If @var{value} is defined, first assigns that.
 @subsection Cortex-M3 specific commands
 @cindex Cortex-M3
 
-@deffn Command {cortex_m3 maskisr} (@option{auto}|@option{on}|@option{off})
+@deffn Command {cortex_m3 maskisr} (@option{on}|@option{off})
 Control masking (disabling) interrupts during target step/resume.
-
-The @option{auto} option handles interrupts during stepping a way they get
-served but don't disturb the program flow. The step command first allows
-pending interrupt handlers to execute, then disables interrupts and steps over
-the next instruction where the core was halted. After the step interrupts
-are enabled again. If the interrupt handlers don't complete within 500ms,
-the step command leaves with the core running.
-
-Note that a free breakpoint is required for the @option{auto} option. If no
-breakpoint is available at the time of the step, then the step is taken
-with interrupts enabled, i.e. the same way the @option{off} option does.
-
-Default is @option{auto}.
 @end deffn
 
 @deffn Command {cortex_m3 vector_catch} [@option{all}|@option{none}|list]
diff --git a/src/target/cortex_m3.c b/src/target/cortex_m3.c
index 98a775c30c6a100378ca35b11ff52224354426e8..9c3d2d9d691ffa9b13f1fd9bbbaa4518f5cc43c5 100644
--- a/src/target/cortex_m3.c
+++ b/src/target/cortex_m3.c
@@ -39,7 +39,6 @@
 #include "register.h"
 #include "arm_opcodes.h"
 #include "arm_semihosting.h"
-#include <helper/time_support.h>
 
 /* NOTE:  most of this should work fine for the Cortex-M1 and
  * Cortex-M0 cores too, although they're ARMv6-M not ARMv7-M.
@@ -859,8 +858,6 @@ static int cortex_m3_step(struct target *target, int current,
 	struct breakpoint *breakpoint = NULL;
 	struct reg *pc = armv7m->arm.pc;
 	bool bkpt_inst_found = false;
-	int retval;
-	bool isr_timed_out = false;
 
 	if (target->state != TARGET_HALTED)
 	{
@@ -894,79 +891,11 @@ static int cortex_m3_step(struct target *target, int current,
 	 * instruction - as such simulate a step */
 	if (bkpt_inst_found == false)
 	{
-		/* Automatic ISR masking mode off: Just step over the next instruction */
-		if ((cortex_m3->isrmasking_mode != CORTEX_M3_ISRMASK_AUTO))
-		{
-			cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
-		}
-		else
-		{
-			/* Process interrupts during stepping in a way they don't interfere
-			 * debugging.
-			 *
-			 * Principle:
-			 *
-			 * Set a temporary break point at the current pc and let the core run
-			 * with interrupts enabled. Pending interrupts get served and we run
-			 * into the breakpoint again afterwards. Then we step over the next
-			 * instruction with interrupts disabled.
-			 *
-			 * If the pending interrupts don't complete within time, we leave the
-			 * core running. This may happen if the interrupts trigger faster
-			 * than the core can process them or the handler doesn't return.
-			 *
-			 * If no more breakpoints are available we simply do a step with
-			 * interrupts enabled.
-			 *
-			 */
-
-			/* Set a temporary break point */
-			retval = breakpoint_add(target, pc_value , 2, BKPT_TYPE_BY_ADDR(pc_value));
-			bool tmp_bp_set = (retval == ERROR_OK);
-
-			/* No more breakpoints left, just do a step */
-			if (!tmp_bp_set)
-			{
-				cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
-			}
-			else
-			{
-				/* Start the core */
-				LOG_DEBUG("Starting core to serve pending interrupts");
-				int64_t t_start = timeval_ms();
-				cortex_m3_write_debug_halt_mask(target, 0, C_HALT | C_STEP);
-
-				/* Wait for pending handlers to complete or timeout */
-				do {
-					retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
-					if (retval != ERROR_OK)
-					{
-						target->state = TARGET_UNKNOWN;
-						return retval;
-					}
-					isr_timed_out = ((timeval_ms() - t_start) > 500);
-				} while (!((cortex_m3->dcb_dhcsr & S_HALT) || isr_timed_out));
-
-				/* Remove the temporary breakpoint */
-				breakpoint_remove(target, pc_value);
-
-				if (isr_timed_out)
-				{
-					LOG_DEBUG("Interrupt handlers didn't complete within time, "
-							"leaving target running");
-				}
-				else
-				{
-					/* Step over next instruction with interrupts disabled */
-					cortex_m3_write_debug_halt_mask(target, C_HALT | C_MASKINTS, 0);
-					cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
-					/* Re-enable interrupts */
-					cortex_m3_write_debug_halt_mask(target, C_HALT, C_MASKINTS);
-				}
-			}
-		}
+		/* set step and clear halt */
+		cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
 	}
 
+	int retval;
 	retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
 	if (retval != ERROR_OK)
 		return retval;
@@ -977,13 +906,6 @@ static int cortex_m3_step(struct target *target, int current,
 	if (breakpoint)
 		cortex_m3_set_breakpoint(target, breakpoint);
 
-	if (isr_timed_out) {
-		/* Leave the core running. The user has to stop execution manually. */
-		target->debug_reason = DBG_REASON_NOTHALTED;
-		target->state = TARGET_RUNNING;
-		return ERROR_OK;
-	}
-
 	LOG_DEBUG("target stepped dcb_dhcsr = 0x%" PRIx32
 			" nvic_icsr = 0x%" PRIx32,
 			cortex_m3->dcb_dhcsr, cortex_m3->nvic_icsr);
@@ -2182,15 +2104,6 @@ COMMAND_HANDLER(handle_cortex_m3_mask_interrupts_command)
 	struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
 	int retval;
 
-	static const Jim_Nvp nvp_maskisr_modes[] = {
-		{ .name = "auto", .value = CORTEX_M3_ISRMASK_AUTO },
-		{ .name = "off" , .value = CORTEX_M3_ISRMASK_OFF },
-		{ .name = "on"  , .value = CORTEX_M3_ISRMASK_ON },
-		{ .name = NULL  , .value = -1 },
-	};
-	const Jim_Nvp *n;
-
-
 	retval = cortex_m3_verify_pointer(CMD_CTX, cortex_m3);
 	if (retval != ERROR_OK)
 		return retval;
@@ -2203,26 +2116,15 @@ COMMAND_HANDLER(handle_cortex_m3_mask_interrupts_command)
 
 	if (CMD_ARGC > 0)
 	{
-		n = Jim_Nvp_name2value_simple(nvp_maskisr_modes, CMD_ARGV[0]);
-		if (n->name == NULL)
-		{
-			return ERROR_COMMAND_SYNTAX_ERROR;
-		}
-		cortex_m3->isrmasking_mode = n->value;
-
-
-		if(cortex_m3->isrmasking_mode == CORTEX_M3_ISRMASK_ON)
-		{
-			cortex_m3_write_debug_halt_mask(target, C_HALT | C_MASKINTS, 0);
-		}
-		else
-		{
-			cortex_m3_write_debug_halt_mask(target, C_HALT, C_MASKINTS);
-		}
+		bool enable;
+		COMMAND_PARSE_ON_OFF(CMD_ARGV[0], enable);
+		uint32_t mask_on = C_HALT | (enable ? C_MASKINTS : 0);
+		uint32_t mask_off = enable ? 0 : C_MASKINTS;
+		cortex_m3_write_debug_halt_mask(target, mask_on, mask_off);
 	}
 
-	n = Jim_Nvp_value2name_simple(nvp_maskisr_modes, cortex_m3->isrmasking_mode);
-	command_print(CMD_CTX, "cortex_m3 interrupt mask %s", n->name);
+	command_print(CMD_CTX, "cortex_m3 interrupt mask %s",
+			(cortex_m3->dcb_dhcsr & C_MASKINTS) ? "on" : "off");
 
 	return ERROR_OK;
 }
@@ -2272,7 +2174,7 @@ static const struct command_registration cortex_m3_exec_command_handlers[] = {
 		.handler = handle_cortex_m3_mask_interrupts_command,
 		.mode = COMMAND_EXEC,
 		.help = "mask cortex_m3 interrupts",
-		.usage = "['auto'|'on'|'off']",
+		.usage = "['on'|'off']",
 	},
 	{
 		.name = "vector_catch",
diff --git a/src/target/cortex_m3.h b/src/target/cortex_m3.h
index e16aa89feb96544664d4997f8e032843656341bd..e1f8ef8039018f642c068cb5216f6f7dfacb6bfc 100644
--- a/src/target/cortex_m3.h
+++ b/src/target/cortex_m3.h
@@ -140,13 +140,6 @@ enum cortex_m3_soft_reset_config
 	CORTEX_M3_RESET_VECTRESET,
 };
 
-enum cortex_m3_isrmasking_mode
-{
-	CORTEX_M3_ISRMASK_AUTO,
-	CORTEX_M3_ISRMASK_OFF,
-	CORTEX_M3_ISRMASK_ON,
-};
-
 struct cortex_m3_common
 {
 	int common_magic;
@@ -173,8 +166,6 @@ struct cortex_m3_common
 
 	enum cortex_m3_soft_reset_config soft_reset_config;
 
-	enum cortex_m3_isrmasking_mode isrmasking_mode;
-
 	struct armv7m_common armv7m;
 };