-DL_DIR:=$(call qstrip,$(if $(CONFIG_DOWNLOAD_FOLDER), $(CONFIG_DOWNLOAD_FOLDER),$(TOPDIR)/dl))
+DL_DIR:=$(if $(call qstrip,$(CONFIG_DOWNLOAD_FOLDER)),$(call qstrip,$(CONFIG_DOWNLOAD_FOLDER)),$(TOPDIR)/dl)
# file extension
ext=$(word $(words $(subst ., ,$(1))),$(subst ., ,$(1)))
# file extension
ext=$(word $(words $(subst ., ,$(1))),$(subst ., ,$(1)))