1 files changed, 30 insertions, 12 deletions
diff --git a/package/base-files/files/etc/init.d/gpio_switch b/package/base-files/files/etc/init.d/gpio_switch
index 6b2dcdce41..24d790b065 100755
--- a/package/base-files/files/etc/init.d/gpio_switch
+++ b/package/base-files/files/etc/init.d/gpio_switch
@@ -16,21 +16,39 @@ load_gpio_switch()
 	config_get name "$1" name
 	config_get value "$1" value 0
 
-	local gpio_path="/sys/class/gpio/gpio${gpio_pin}"
-	# export GPIO pin for access
-	[ -d "$gpio_path" ] || {
-		echo "$gpio_pin" >/sys/class/gpio/export
-		# we need to wait a bit until the GPIO appears
-		[ -d "$gpio_path" ] || sleep 1
+	[ -z "$gpio_pin" ] && {
+		echo >&2 "Skipping gpio_switch '$name' due to missing gpio_pin"
+		return 1
 	}
 
-	# direction attribute only exists if the kernel supports changing the
-	# direction of a GPIO
-	if [ -e "${gpio_path}/direction" ]; then
-		# set the pin to output with high or low pin value
-		{ [ "$value" = "0" ] && echo "low" || echo "high"; } >"$gpio_path/direction"
+	local gpio_path
+	if [ -n "$(echo "$gpio_pin" | grep -E "^[0-9]+$")" ]; then
+		gpio_path="/sys/class/gpio/gpio${gpio_pin}"
+
+		# export GPIO pin for access
+		[ -d "$gpio_path" ] || {
+			echo "$gpio_pin" >/sys/class/gpio/export
+			# we need to wait a bit until the GPIO appears
+			[ -d "$gpio_path" ] || sleep 1
+		}
+
+		# direction attribute only exists if the kernel supports changing the
+		# direction of a GPIO
+		if [ -e "${gpio_path}/direction" ]; then
+			# set the pin to output with high or low pin value
+			{ [ "$value" = "0" ] && echo "low" || echo "high"; } \
+				>"$gpio_path/direction"
+		else
+			{ [ "$value" = "0" ] && echo "0" || echo "1"; } \
+				>"$gpio_path/value"
+		fi
 	else
-		{ [ "$value" = "0" ] && echo "0" || echo "1"; } >"$gpio_path/value"
+		gpio_path="/sys/class/gpio/${gpio_pin}"
+
+		[ -d "$gpio_path" ] && {
+			{ [ "$value" = "0" ] && echo "0" || echo "1"; } \
+				>"$gpio_path/value"
+		}
 	fi
 }