ACPICA: Debug output: Do not emit function nesting level for kernel build.

The nesting level is really only useful during a single-thread
execution. Therefore, only enable this output for the AcpiExec
utility. Also, only emit the thread ID when executing under AcpiExec.
(Context switches are still detected and a message is emitted.)
ACPICA BZ 972.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/utdebug.c

@@ -185,6 +185,7 @@ acpi_debug_print(u32 requested_debug_level,
 		}
 
 		acpi_gbl_prev_thread_id = thread_id;
+		acpi_gbl_nesting_level = 0;
 	}
 
 	/*
@@ -193,13 +194,21 @@ acpi_debug_print(u32 requested_debug_level,
 	 */
 	acpi_os_printf("%9s-%04ld ", module_name, line_number);
 
+#ifdef ACPI_EXEC_APP
+	/*
+	 * For acpi_exec only, emit the thread ID and nesting level.
+	 * Note: nesting level is really only useful during a single-thread
+	 * execution. Otherwise, multiple threads will keep resetting the
+	 * level.
+	 */
 	if (ACPI_LV_THREADS & acpi_dbg_level) {
 		acpi_os_printf("[%u] ", (u32)thread_id);
 	}
 
-	acpi_os_printf("[%02ld] %-22.22s: ",
-		       acpi_gbl_nesting_level,
-		       acpi_ut_trim_function_name(function_name));
+	acpi_os_printf("[%02ld] ", acpi_gbl_nesting_level);
+#endif
+
+	acpi_os_printf("%-22.22s: ", acpi_ut_trim_function_name(function_name));
 
 	va_start(args, format);
 	acpi_os_vprintf(format, args);
@@ -420,7 +429,9 @@ acpi_ut_exit(u32 line_number,
 				 component_id, "%s\n", acpi_gbl_fn_exit_str);
 	}
 
-	acpi_gbl_nesting_level--;
+	if (acpi_gbl_nesting_level) {
+		acpi_gbl_nesting_level--;
+	}
 }
 
 ACPI_EXPORT_SYMBOL(acpi_ut_exit)
@@ -467,7 +478,9 @@ acpi_ut_status_exit(u32 line_number,
 		}
 	}
 
-	acpi_gbl_nesting_level--;
+	if (acpi_gbl_nesting_level) {
+		acpi_gbl_nesting_level--;
+	}
 }
 
 ACPI_EXPORT_SYMBOL(acpi_ut_status_exit)
@@ -504,7 +517,9 @@ acpi_ut_value_exit(u32 line_number,
 				 ACPI_FORMAT_UINT64(value));
 	}
 
-	acpi_gbl_nesting_level--;
+	if (acpi_gbl_nesting_level) {
+		acpi_gbl_nesting_level--;
+	}
 }
 
 ACPI_EXPORT_SYMBOL(acpi_ut_value_exit)
@@ -540,7 +555,9 @@ acpi_ut_ptr_exit(u32 line_number,
 				 ptr);
 	}
 
-	acpi_gbl_nesting_level--;
+	if (acpi_gbl_nesting_level) {
+		acpi_gbl_nesting_level--;
+	}
 }
 
 #endif