tty: drop interrupt-safety todo

This is better handled as work.

kernel-src/io/serial/pc_com.c

@@ -183,7 +183,6 @@ static size_t write_tty(void *internal, char *str, size_t size) {
 	return size;
 }
 
-// TODO enqueue dpc and call tty_process directly from it once it is safe to be called from an interrupt context
 static void irq(isr_t *self, context_t *) {
 	pc_com_t *pc_com = self->priv;
 

kernel-src/io/tty.c

@@ -43,14 +43,6 @@ static int setforeground(tty_t *tty, proc_t *proc) {
 	return ENOTTY;
 }
 
-// TODO: make this interrupt safe
-// this would mean:
-// - preventing the leaders from reaching refcnt = 1 during the getforeground() call until it is done
-// - list mutex -> list spinlock
-//
-// however, for it to truly be interrupt safe, the tty->writetodevice callback would also need to be interrupt safe,
-// which means that any drivers expecting to call this from an interrupt context would REQUIRE to have the callback to also be interrupt safe
-// the main console is an example of a driver which would not be able to do so.
 void tty_process(tty_t *tty, char c) {
 	if (c == '\r' && (tty->termios.c_iflag & IGNCR))
 		return;