FM / parameters

/sys/module/8250/parameters

Name	Size	Mode	Actions
nr_uarts	4096	0644	edit dl rm
probe_rsa	4096	0444	edit dl rm
share_irqs	4096	0644	edit dl rm
skip_txen_test	4096	0644	edit dl rm

Edit: /sys/module/8250/parameters/nr_uarts (4096B)