If c->cdev->use_os_string flag is not set, don't need to invoke ffs_do_os_descs() in _ffs_func_bind. So uninitialized ext_compat_id pointer won't be accessed by __ffs_func_bind_do_os_desc to cause kernel panic. Signed-off-by: Jim Lin <jilin@nvidia.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>