diff --git a/cdba-power.c b/cdba-power.c
index 8d3f786..d8902d2 100644
--- a/cdba-power.c
+++ b/cdba-power.c
@@ -23,6 +23,7 @@ void cdba_send_buf(int type, size_t len, const void *buf)
 static void usage(const char *name)
 {
 	fprintf(stderr, "Usage: %s <board> on|off\n", name);
+	fprintf(stderr, "Usage: %s all-off\n", name);
 	exit(EXIT_FAILURE);
 }
 
@@ -33,22 +34,47 @@ bool ready(void)
 	return device_is_running(selected_device);
 }
 
+static int all_off(void)
+{
+	struct device *next = NULL, *dev;
+	int ret = 0;
+
+	while ((next = device_next(next))) {
+		dev = device_open_power_only(next->board, "nobody");
+		if (!dev) {
+			fprintf(stderr, "failed to open %s\n", next->board);
+			ret = EXIT_FAILURE;
+			continue;
+		}
+
+		device_usb(dev, false);
+		device_power_off(dev);
+		device_close(dev);
+	}
+
+	return ret;
+}
+
 int main(int argc, char **argv)
 {
 	const char *home;
 	const char *name;
+	bool all = false;
 	bool on;
 	int ret;
 
-	if (argc != 3)
-		usage(argv[0]);
-
-	if (!strcmp(argv[2], "on"))
-		on = true;
-	else if (!strcmp(argv[2], "off"))
-		on = false;
-	else
+	if (argc == 2 && !strcmp(argv[1], "all-off")) {
+		all = true;
+	} else if (argc == 3) {
+		if (!strcmp(argv[2], "on"))
+			on = true;
+		else if (!strcmp(argv[2], "off"))
+			on = false;
+		else
+			usage(argv[0]);
+	} else {
 		usage(argv[0]);
+	}
 
 	home = getenv("HOME");
 	if (home)
@@ -63,6 +89,9 @@ int main(int argc, char **argv)
 		}
 	}
 
+	if (all)
+		return all_off();
+
 	name = argv[1];
 	selected_device = device_open(name, "nobody");
 	if (!selected_device) {
diff --git a/device.c b/device.c
index 8b76524..3380507 100644
--- a/device.c
+++ b/device.c
@@ -49,6 +49,17 @@ void device_add(struct device *device)
 	list_append(&devices, &device->node);
 }
 
+struct device *device_next(struct device *device)
+{
+	struct list_head *item;
+
+	item = device ? device->node.next : devices.next;
+	if (item == &devices)
+		return NULL;
+
+	return list_entry(item, struct device, node);
+}
+
 static void device_lock(struct device *device)
 {
 	char lock[PATH_MAX];
@@ -103,8 +114,8 @@ static bool device_check_access(struct device *device,
 	return false;
 }
 
-struct device *device_open(const char *board,
-			   const char *username)
+static struct device *__device_open(const char *board, const char *username,
+				    bool power_only)
 {
 	struct device *device;
 
@@ -133,10 +144,20 @@ struct device *device_open(const char *board,
 
 	if (device_has_control(device, open)) {
 		device->cdb = device_control(device, open);
-		if (!device->cdb)
+		if (!device->cdb) {
+			if (power_only) {
+				warnx("failed to open device controller for %s",
+				      board);
+				return NULL;
+			}
 			errx(1, "failed to open device controller");
+		}
 	}
 
+	/* Switching power and USB off needs neither console nor fastboot. */
+	if (power_only)
+		return device;
+
 	device->console = device_console(device, open);
 	if (!device->console)
 		errx(1, "failed to open device console");
@@ -159,6 +180,20 @@ struct device *device_open(const char *board,
 	return device;
 }
 
+struct device *device_open(const char *board, const char *username)
+{
+	return __device_open(board, username, false);
+}
+
+/*
+ * Open only the board's controller (no console), enough to switch power and
+ * USB off. Unlike device_open() this doesn't exit if the console is missing.
+ */
+struct device *device_open_power_only(const char *board, const char *username)
+{
+	return __device_open(board, username, true);
+}
+
 static void device_impl_power(struct device *device, bool on)
 {
 	device_control(device, power, on);
diff --git a/device.h b/device.h
index 664f942..54a6aaa 100644
--- a/device.h
+++ b/device.h
@@ -94,9 +94,12 @@ struct device_qdl_user {
 };
 
 void device_add(struct device *device);
+struct device *device_next(struct device *device);
 
 struct device *device_open(const char *board,
 			   const char *username);
+struct device *device_open_power_only(const char *board,
+				      const char *username);
 void device_close(struct device *dev);
 int device_power_on(struct device *device, enum power_on_mode mode);
 int device_power_off(struct device *device);
diff --git a/drivers/alpaca.c b/drivers/alpaca.c
index f720670..37628fb 100644
--- a/drivers/alpaca.c
+++ b/drivers/alpaca.c
@@ -38,8 +38,10 @@ static void *alpaca_open(struct device *dev)
 	alpaca = calloc(1, sizeof(*alpaca));
 
 	alpaca->alpaca_fd = tty_open(dev->control_dev, &alpaca->alpaca_tios);
-	if (alpaca->alpaca_fd < 0)
-		err(1, "failed to open %s", dev->control_dev);
+	if (alpaca->alpaca_fd < 0) {
+		free(alpaca);
+		return NULL;
+	}
 
 	alpaca_device_power(alpaca, 0);
 
diff --git a/drivers/ftdi-gpio.c b/drivers/ftdi-gpio.c
index 070b3d3..52c7442 100644
--- a/drivers/ftdi-gpio.c
+++ b/drivers/ftdi-gpio.c
@@ -308,9 +308,18 @@ static void *ftdi_gpio_open(struct device *dev)
 
 		ret = ftdi_usb_open_string(ftdi_gpio->interface[ftdi_interface],
 					   ftdi_gpio->options->ftdi.description);
-		if (ret < 0)
-			errx(1, "failed to open ftdi gpio device '%s' (%d)",
-			     ftdi_gpio->options->ftdi.description, ret);
+		if (ret < 0) {
+			warnx("failed to open ftdi gpio device '%s' (%d)",
+			      ftdi_gpio->options->ftdi.description, ret);
+			for (i = 0; i < FTDI_INTERFACE_COUNT; ++i) {
+				if (!ftdi_gpio->interface[i])
+					continue;
+				ftdi_usb_close(ftdi_gpio->interface[i]);
+				ftdi_free(ftdi_gpio->interface[i]);
+			}
+			free(ftdi_gpio);
+			return NULL;
+		}
 
 		ftdi_set_bitmode(ftdi_gpio->interface[ftdi_interface],
 				 0xFF, BITMODE_BITBANG);
diff --git a/drivers/pic32cx.c b/drivers/pic32cx.c
index 0049fe1..ea032b4 100644
--- a/drivers/pic32cx.c
+++ b/drivers/pic32cx.c
@@ -49,8 +49,10 @@ static void *pic32cx_open(struct device *dev)
 	pic32cx = calloc(1, sizeof(*pic32cx));
 
 	pic32cx->fd = tty_open(dev->control_dev, &pic32cx->tios);
-	if (pic32cx->fd < 0)
-		err(1, "failed to open %s", dev->control_dev);
+	if (pic32cx->fd < 0) {
+		free(pic32cx);
+		return NULL;
+	}
 
 	pic32cx_device_power(pic32cx, 1);
 
diff --git a/drivers/qcomlt_dbg.c b/drivers/qcomlt_dbg.c
index fe55cf4..d058955 100644
--- a/drivers/qcomlt_dbg.c
+++ b/drivers/qcomlt_dbg.c
@@ -52,8 +52,10 @@ static void *qcomlt_dbg_open(struct device *dev)
 	dbg = calloc(1, sizeof(*dbg));
 
 	dbg->fd = tty_open(dev->control_dev, &dbg->orig_tios);
-	if (dbg->fd < 0)
-		err(1, "failed to open %s", dev->control_dev);
+	if (dbg->fd < 0) {
+		free(dbg);
+		return NULL;
+	}
 
 	// fprintf(stderr, "qcomlt_dbg_open()\n");
 	write(dbg->fd, "brpu", 4);
diff --git a/tty.c b/tty.c
index 4c75cfe..e4f49a1 100644
--- a/tty.c
+++ b/tty.c
@@ -20,8 +20,10 @@ int tty_open(const char *tty, struct termios *old)
 	int fd;
 
 	fd = open(tty, O_RDWR | O_NOCTTY | O_EXCL);
-	if (fd < 0)
-		err(1, "unable to open \"%s\"", tty);
+	if (fd < 0) {
+		warn("unable to open \"%s\"", tty);
+		return -1;
+	}
 
 	ret = tcgetattr(fd, old);
 	if (ret < 0)