ACPICA: Fix implementation of AML BreakPoint operator (break to debugger)

The AML BreakPoint opcode will now cause a break into the AML
debugger if it is present/configured. This matches the expected
behavior per the ACPI specification. Previously, only a message
was output.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 11 insertions, 6 deletions

diff --git a/drivers/acpi/acpica/dsopcode.c b/drivers/acpi/acpica/dsopcode.c
index b4c87b5053e6..584d766e6f12 100644
--- a/drivers/acpi/acpica/dsopcode.c
+++ b/drivers/acpi/acpica/dsopcode.c
@@ -1386,14 +1386,19 @@ acpi_ds_exec_end_control_op(struct acpi_walk_state * walk_state,
 
         case AML_BREAK_POINT_OP:
 
-                /* Call up to the OS service layer to handle this */
-
-                status =
-                    acpi_os_signal(ACPI_SIGNAL_BREAKPOINT,
-                                   "Executed AML Breakpoint opcode");
+                /*
+                 * Set the single-step flag. This will cause the debugger (if present)
+                 * to break to the console within the AML debugger at the start of the
+                 * next AML instruction.
+                 */
+                ACPI_DEBUGGER_EXEC(acpi_gbl_cm_single_step = TRUE);
+                ACPI_DEBUGGER_EXEC(acpi_os_printf
+                                   ("**break** Executed AML BreakPoint opcode\n"));
 
-                /* If and when it returns, all done. */
+                /* Call to the OSL in case OS wants a piece of the action */
 
+                status = acpi_os_signal(ACPI_SIGNAL_BREAKPOINT,
+                                        "Executed AML Breakpoint opcode");
                 break;
 
         case AML_BREAK_OP: