--- nslink.c.orig	2021-08-10 16:38:55.351971026 -0400
+++ nslink.c	2021-08-10 16:40:03.424715195 -0400
@@ -2505,14 +2505,16 @@ static void init_nr_port(struct si_state
         info->close_delay = 500;     //ms
         info->baud_rate = 9600;
         info->baud_base = 0;
         // don't set low latency flag on MAC-mode ports, or it causes
         // problems when tty_flip_buffer_push() is called
+#if LINUX_VERSION_CODE < VERSION_CODE(5,12,0)
         if (low_latency && si->use_tcp)
                 info->port.flags |= ASYNC_LOW_LATENCY;
         else
                 info->port.flags &= ~ASYNC_LOW_LATENCY;
+#endif
         info->rx_fifo_disable = rx_fifo_disable;
 
         // check for invalid RS mode setting
 
         if (UnitHasOnly232(si->modelID) && (si->rsmode[portnum] != SI_RSMODE_232)) {
@@ -3311,12 +3313,14 @@ static int set_serial_info(struct nr_por
         if (new_serial.closing_wait != ASYNC_CLOSING_WAIT_NONE)
                 new_serial.closing_wait *= 10;
 
         // don't allow low_latency mode in MAC mode since it causes problems
         // when tty_flip_buffer_push() is called.
+#if LINUX_VERSION_CODE < VERSION_CODE(5,12,0)
         if (!info->si->use_tcp)
                 new_serial.flags &= ~ASYNC_LOW_LATENCY;
+#endif
 
 #ifdef CAP_SYS_ADMIN
         if (!capable(CAP_SYS_ADMIN))
 #else
         if (!suser())
@@ -3333,12 +3337,14 @@ static int set_serial_info(struct nr_por
         }
 
         info->baud_base = new_serial.baud_base;
         info->custom_divisor = new_serial.custom_divisor;
 
+#if LINUX_VERSION_CODE < VERSION_CODE(5,12,0)
         if (info->tty)
                 nrp_tty_is_low_latency(info->tty) =  (info->port.flags & ASYNC_LOW_LATENCY) != 0;
+#endif
 
         info->inter_char_timeout = new_serial.irq;
         if (UnitHasNewTimeoutCommands(info->si))
                 info->update_ic_timeout = 1;
 
@@ -3786,17 +3792,19 @@ static int nrp_write(struct tty_struct *
 
 end:
         up(&info->write_sem);
 
         //  Call the routines to send data to hub
+#if LINUX_VERSION_CODE < VERSION_CODE(5,12,0)
         if (info->tty && nrp_tty_is_low_latency(info->tty)) {
                 info->si->need_to_send = 1;
                 if (info->si->use_tcp == 0)
                         si_timer((callback_param_type)&info->si->timer);
                 else
                         tcp_send_remote_cmds(info->si);
         }
+#endif
 #ifdef NSLINK_DEBUG_WRITE
         printk(KERN_INFO "ret=%d\n", retval);
 #endif
 
         return retval;