Check all inputs before changing anything, and return the right error code in case of failure. Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de> Link: https://lore.kernel.org/r/20230422161021.1144026-1-oswald.buddenhagen@gmx.de Signed-off-by: Takashi Iwai <tiwai@suse.de>