diff -pNaru5 a/ax99100_sp.h b/ax99100_sp.h
--- a/ax99100_sp.h	2022-06-07 16:55:26.621034945 -0400
+++ b/ax99100_sp.h	2022-06-07 16:58:32.488989767 -0400
@@ -255,5 +255,10 @@ struct custom_eeprom {
 #define _INLINE_
 #endif
 
 #define DEFAULT99100_BAUD 115200
 #endif
+
+/* #if LINUX_VERSION_CODE >= KERNEL_VERSION(5,18,0) */
+#define pci_alloc_consistent(hwdev,size,dma_handle) dma_alloc_coherent(&hwdev->dev, size, dma_handle, GFP_ATOMIC)
+#define pci_free_consistent(hwdev,size,vaddr,dma_handle) dma_free_coherent(&hwdev->dev, size, vaddr, dma_handle)
+/* #endif */