diff --git a/kconfig/conf.c b/kconfig/conf.c
index 67e32197..dd714b48 100644
--- a/kconfig/conf.c
+++ b/kconfig/conf.c
@@ -90,7 +90,7 @@ static int conf_askvalue(struct symbol *sym, const char *def)
 	line[0] = '\n';
 	line[1] = 0;
 
-	if (!sym_is_changable(sym)) {
+	if (!sym_is_changeable(sym)) {
 		printf("%s\n", def);
 		line[0] = '\n';
 		line[1] = 0;
@@ -234,7 +234,7 @@ static int conf_choice(struct menu *menu)
 
 	sym = menu->sym;
 	is_new = !sym_has_value(sym);
-	if (sym_is_changable(sym)) {
+	if (sym_is_changeable(sym)) {
 		conf_sym(menu);
 		sym_calc_value(sym);
 		switch (sym_get_tristate_value(sym)) {
@@ -418,7 +418,7 @@ static void check_conf(struct menu *menu)
 
 	sym = menu->sym;
 	if (sym && !sym_has_value(sym)) {
-		if (sym_is_changable(sym) ||
+		if (sym_is_changeable(sym) ||
 		    (sym_is_choice(sym) && sym_get_tristate_value(sym) == yes)) {
 			if (input_mode == listnewconfig) {
 				if (sym->name) {
@@ -451,7 +451,7 @@ static struct option long_opts[] = {
 	{"oldaskconfig",    no_argument,       NULL, oldaskconfig},
 	{"oldconfig",       no_argument,       NULL, oldconfig},
 	{"syncconfig",      no_argument,       NULL, syncconfig},
-	{"defconfig",       optional_argument, NULL, defconfig},
+	{"defconfig",       required_argument, NULL, defconfig},
 	{"savedefconfig",   required_argument, NULL, savedefconfig},
 	{"allnoconfig",     no_argument,       NULL, allnoconfig},
 	{"allyesconfig",    no_argument,       NULL, allyesconfig},
@@ -542,8 +542,6 @@ int main(int ac, char **av)
 
 	switch (input_mode) {
 	case defconfig:
-		if (!defconfig_file)
-			defconfig_file = conf_get_default_confname();
 		if (conf_read(defconfig_file)) {
 			fprintf(stderr,
 				"***\n"
diff --git a/kconfig/confdata.c b/kconfig/confdata.c
index 6006154d..3569d2de 100644
--- a/kconfig/confdata.c
+++ b/kconfig/confdata.c
@@ -177,8 +177,6 @@ static void conf_message(const char *fmt, ...)
 static const char *conf_filename;
 static int conf_lineno, conf_warnings;
 
-const char conf_defname[] = "arch/$(ARCH)/defconfig";
-
 static void conf_warning(const char *fmt, ...)
 {
 	va_list ap;
@@ -233,21 +231,6 @@ static const char *conf_get_autoconfig_name(void)
 	return name ? name : "include/config/auto.conf";
 }
 
-char *conf_get_default_confname(void)
-{
-	static char fullname[PATH_MAX+1];
-	char *env, *name;
-
-	name = expand_string(conf_defname);
-	env = getenv(SRCTREE);
-	if (env) {
-		snprintf(fullname, sizeof(fullname), "%s/%s", env, name);
-		if (is_present(fullname))
-			return fullname;
-	}
-	return name;
-}
-
 static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 {
 	char *p2;
@@ -551,11 +534,9 @@ int conf_read(const char *name)
 			switch (sym->type) {
 			case S_BOOLEAN:
 			case S_TRISTATE:
-				if (sym->def[S_DEF_USER].tri != sym_get_tristate_value(sym))
-					break;
-				if (!sym_is_choice(sym))
+				if (sym->def[S_DEF_USER].tri == sym_get_tristate_value(sym))
 					continue;
-				/* fall through */
+				break;
 			default:
 				if (!strcmp(sym->curr.val, sym->def[S_DEF_USER].val))
 					continue;
@@ -813,7 +794,7 @@ int conf_write_defconfig(const char *filename)
 				goto next_menu;
 			sym->flags &= ~SYMBOL_WRITE;
 			/* If we cannot change the symbol - skip */
-			if (!sym_is_changable(sym))
+			if (!sym_is_changeable(sym))
 				goto next_menu;
 			/* If symbol equals to default value - skip */
 			if (strcmp(sym_get_string_value(sym), sym_get_string_default(sym)) == 0)
@@ -867,6 +848,7 @@ int conf_write(const char *name)
 	const char *str;
 	char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1];
 	char *env;
+	int i;
 	bool need_newline = false;
 
 	if (!name)
@@ -914,7 +896,8 @@ int conf_write(const char *name)
 				     "# %s\n"
 				     "#\n", str);
 			need_newline = false;
-		} else if (!(sym->flags & SYMBOL_CHOICE)) {
+		} else if (!(sym->flags & SYMBOL_CHOICE) &&
+			   !(sym->flags & SYMBOL_WRITTEN)) {
 			sym_calc_value(sym);
 			if (!(sym->flags & SYMBOL_WRITE))
 				goto next;
@@ -922,7 +905,7 @@ int conf_write(const char *name)
 				fprintf(out, "\n");
 				need_newline = false;
 			}
-			sym->flags &= ~SYMBOL_WRITE;
+			sym->flags |= SYMBOL_WRITTEN;
 			conf_write_symbol(out, sym, &kconfig_printer_cb, NULL);
 		}
 
@@ -948,6 +931,9 @@ next:
 	}
 	fclose(out);
 
+	for_all_symbols(i, sym)
+		sym->flags &= ~SYMBOL_WRITTEN;
+
 	if (*tmpname) {
 		if (is_same(name, tmpname)) {
 			conf_message("No change to %s", name);
@@ -1082,8 +1068,6 @@ int conf_write_autoconf(int overwrite)
 	if (!overwrite && is_present(autoconf_name))
 		return 0;
 
-	sym_clear_all_valid();
-
 	conf_write_dep("include/config/auto.conf.cmd");
 
 	if (conf_touch_deps())
diff --git a/kconfig/expr.h b/kconfig/expr.h
index 8dde65bc..017843c9 100644
--- a/kconfig/expr.h
+++ b/kconfig/expr.h
@@ -141,6 +141,7 @@ struct symbol {
 #define SYMBOL_OPTIONAL   0x0100  /* choice is optional - values can be 'n' */
 #define SYMBOL_WRITE      0x0200  /* write symbol to file (KCONFIG_CONFIG) */
 #define SYMBOL_CHANGED    0x0400  /* ? */
+#define SYMBOL_WRITTEN    0x0800  /* track info to avoid double-write to .config */
 #define SYMBOL_NO_WRITE   0x1000  /* Symbol for internal use only; it will not be written */
 #define SYMBOL_CHECKED    0x2000  /* used during dependency checking */
 #define SYMBOL_WARNED     0x8000  /* warning has been issued */
diff --git a/kconfig/lkc.h b/kconfig/lkc.h
index cbc7658e..4fb16f31 100644
--- a/kconfig/lkc.h
+++ b/kconfig/lkc.h
@@ -49,7 +49,6 @@ const char *zconf_curname(void);
 
 /* confdata.c */
 const char *conf_get_configname(void);
-char *conf_get_default_confname(void);
 void sym_set_change_count(int count);
 void sym_add_change_count(int count);
 bool conf_set_all_new_symbols(enum conf_def_mode mode);
diff --git a/kconfig/lkc_proto.h b/kconfig/lkc_proto.h
index 86c26754..f9ab9823 100644
--- a/kconfig/lkc_proto.h
+++ b/kconfig/lkc_proto.h
@@ -42,7 +42,7 @@ tristate sym_toggle_tristate_value(struct symbol *sym);
 bool sym_string_valid(struct symbol *sym, const char *newval);
 bool sym_string_within_range(struct symbol *sym, const char *str);
 bool sym_set_string_value(struct symbol *sym, const char *newval);
-bool sym_is_changable(struct symbol *sym);
+bool sym_is_changeable(struct symbol *sym);
 struct property * sym_get_choice_prop(struct symbol *sym);
 const char * sym_get_string_value(struct symbol *sym);
 
@@ -58,7 +58,6 @@ void env_write_dep(FILE *f, const char *auto_conf_name);
 void variable_add(const char *name, const char *value,
 		  enum variable_flavor flavor);
 void variable_all_del(void);
-char *expand_string(const char *in);
 char *expand_dollar(const char **str);
 char *expand_one_token(const char **str);
 
diff --git a/kconfig/mconf.c b/kconfig/mconf.c
index 0d775ce7..e3cb6809 100644
--- a/kconfig/mconf.c
+++ b/kconfig/mconf.c
@@ -536,7 +536,7 @@ static void build_conf(struct menu *menu)
 		}
 
 		val = sym_get_tristate_value(sym);
-		if (sym_is_changable(sym)) {
+		if (sym_is_changeable(sym)) {
 			switch (type) {
 			case S_BOOLEAN:
 				item_make("[%c]", val == no ? ' ' : '*');
@@ -587,7 +587,7 @@ static void build_conf(struct menu *menu)
 		} else {
 			switch (type) {
 			case S_BOOLEAN:
-				if (sym_is_changable(sym))
+				if (sym_is_changeable(sym))
 					item_make("[%c]", val == no ? ' ' : '*');
 				else
 					item_make("-%c-", val == no ? ' ' : '*');
@@ -600,7 +600,7 @@ static void build_conf(struct menu *menu)
 				case mod: ch = 'M'; break;
 				default:  ch = ' '; break;
 				}
-				if (sym_is_changable(sym)) {
+				if (sym_is_changeable(sym)) {
 					if (sym->rev_dep.tri == mod)
 						item_make("{%c}", ch);
 					else
@@ -617,7 +617,7 @@ static void build_conf(struct menu *menu)
 				if (tmp < 0)
 					tmp = 0;
 				item_add_str("%*c%s%s", tmp, ' ', menu_get_prompt(menu),
-					     (sym_has_value(sym) || !sym_is_changable(sym)) ?
+					     (sym_has_value(sym) || !sym_is_changeable(sym)) ?
 					     "" : " (NEW)");
 				item_set_tag('s');
 				item_set_data(menu);
@@ -625,7 +625,7 @@ static void build_conf(struct menu *menu)
 			}
 		}
 		item_add_str("%*c%s%s", indent + 1, ' ', menu_get_prompt(menu),
-			  (sym_has_value(sym) || !sym_is_changable(sym)) ?
+			  (sym_has_value(sym) || !sym_is_changeable(sym)) ?
 			  "" : " (NEW)");
 		if (menu->prompt->type == P_MENU) {
 			item_add_str("  %s", menu_is_empty(menu) ? "----" : "--->");
diff --git a/kconfig/nconf.c b/kconfig/nconf.c
index fca2cea6..bee51359 100644
--- a/kconfig/nconf.c
+++ b/kconfig/nconf.c
@@ -806,7 +806,7 @@ static void build_conf(struct menu *menu)
 		}
 
 		val = sym_get_tristate_value(sym);
-		if (sym_is_changable(sym)) {
+		if (sym_is_changeable(sym)) {
 			switch (type) {
 			case S_BOOLEAN:
 				item_make(menu, 't', "[%c]",
@@ -860,7 +860,7 @@ static void build_conf(struct menu *menu)
 		} else {
 			switch (type) {
 			case S_BOOLEAN:
-				if (sym_is_changable(sym))
+				if (sym_is_changeable(sym))
 					item_make(menu, 't', "[%c]",
 						val == no ? ' ' : '*');
 				else
@@ -879,7 +879,7 @@ static void build_conf(struct menu *menu)
 					ch = ' ';
 					break;
 				}
-				if (sym_is_changable(sym)) {
+				if (sym_is_changeable(sym)) {
 					if (sym->rev_dep.tri == mod)
 						item_make(menu,
 							't', "{%c}", ch);
@@ -899,14 +899,14 @@ static void build_conf(struct menu *menu)
 				item_add_str("%*c%s%s", tmp, ' ',
 						menu_get_prompt(menu),
 						(sym_has_value(sym) ||
-						 !sym_is_changable(sym)) ? "" :
+						 !sym_is_changeable(sym)) ? "" :
 						" (NEW)");
 				goto conf_childs;
 			}
 		}
 		item_add_str("%*c%s%s", indent + 1, ' ',
 				menu_get_prompt(menu),
-				(sym_has_value(sym) || !sym_is_changable(sym)) ?
+				(sym_has_value(sym) || !sym_is_changeable(sym)) ?
 				"" : " (NEW)");
 		if (menu->prompt && menu->prompt->type == P_MENU) {
 			item_add_str("  %s", menu_is_empty(menu) ? "----" : "--->");
diff --git a/kconfig/preprocess.c b/kconfig/preprocess.c
index 592dfbfa..0243086f 100644
--- a/kconfig/preprocess.c
+++ b/kconfig/preprocess.c
@@ -15,6 +15,7 @@
 #define ARRAY_SIZE(arr)		(sizeof(arr) / sizeof((arr)[0]))
 
 static char *expand_string_with_args(const char *in, int argc, char *argv[]);
+static char *expand_string(const char *in);
 
 static void __attribute__((noreturn)) pperror(const char *format, ...)
 {
@@ -550,7 +551,7 @@ static char *expand_string_with_args(const char *in, int argc, char *argv[])
 	return __expand_string(&in, is_end_of_str, argc, argv);
 }
 
-char *expand_string(const char *in)
+static char *expand_string(const char *in)
 {
 	return expand_string_with_args(in, 0, NULL);
 }
diff --git a/kconfig/symbol.c b/kconfig/symbol.c
index 1f9266da..f56eec5e 100644
--- a/kconfig/symbol.c
+++ b/kconfig/symbol.c
@@ -785,7 +785,7 @@ const char *sym_get_string_value(struct symbol *sym)
 	return (const char *)sym->curr.val;
 }
 
-bool sym_is_changable(struct symbol *sym)
+bool sym_is_changeable(struct symbol *sym)
 {
 	return sym->visible > sym->rev_dep.tri;
 }
@@ -1114,7 +1114,7 @@ static void sym_check_print_recursive(struct symbol *last_sym)
 	}
 
 	fprintf(stderr,
-		"For a resolution refer to Documentation/kbuild/kconfig-language.txt\n"
+		"For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
 		"subsection \"Kconfig recursive dependency limitations\"\n"
 		"\n");