Index: linux-5.10.21-rt34/drivers/net/ethernet/faraday/ftgmac030/netdev.c
===================================================================
--- linux-5.10.21-rt34.orig/drivers/net/ethernet/faraday/ftgmac030/netdev.c
+++ linux-5.10.21-rt34/drivers/net/ethernet/faraday/ftgmac030/netdev.c
@@ -1849,7 +1849,11 @@ static irqreturn_t ftgmac030_intr(int __
 
 	e_dbg(intr, "[ISR] = 0x%x\n", ior32(FTGMAC030_REG_ISR));
 
+#if defined(CONFIG_PREEMPT_RT)
+	iow32(FTGMAC030_REG_IER, 0);
+#else
 	ftgmac030_irq_disable(ctrl);
+#endif
 
 	if (test_bit(__FTGMAC030_DOWN, &ctrl->state)) {
 		e_info(intr, "[ISR] Not ours\n");