Use IEEE80211_MAX_AMPDU_BUF_HT on kernel 4.19+

torvalds/linux@b8042b3

include/wifi.h

@@ -1027,7 +1027,12 @@ typedef enum _HT_CAP_AMPDU_DENSITY {
  * According to IEEE802.11n spec size varies from 8K to 64K (in powers of 2)
  */
 #define IEEE80211_MIN_AMPDU_BUF 0x8
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)
+#define IEEE80211_MAX_AMPDU_BUF_HT 0x40
+#define IEEE80211_MAX_AMPDU_BUF 0x100
+#else
 #define IEEE80211_MAX_AMPDU_BUF 0x40
+#endif
 
 
 /* Spatial Multiplexing Power Save Modes */