diff --git a/WHENCE b/WHENCE
index 67ea655a..96992460 100644
--- a/WHENCE
+++ b/WHENCE
@@ -578,14 +578,14 @@ Driver: cxgb4 - Chelsio Terminator 4/5/6 1/10/25/40/100G Ethernet adapter
 
 File: cxgb4/t4fw-1.14.4.0.bin
 File: cxgb4/t4fw-1.15.37.0.bin
-File: cxgb4/t4fw-1.24.17.0.bin
-Link: cxgb4/t4fw.bin -> t4fw-1.24.17.0.bin
+File: cxgb4/t4fw-1.25.4.0.bin
+Link: cxgb4/t4fw.bin -> t4fw-1.25.4.0.bin
 File: cxgb4/t5fw-1.14.4.0.bin
 File: cxgb4/t5fw-1.15.37.0.bin
-File: cxgb4/t5fw-1.24.17.0.bin
-Link: cxgb4/t5fw.bin -> t5fw-1.24.17.0.bin
-File: cxgb4/t6fw-1.24.17.0.bin
-Link: cxgb4/t6fw.bin -> t6fw-1.24.17.0.bin
+File: cxgb4/t5fw-1.25.4.0.bin
+Link: cxgb4/t5fw.bin -> t5fw-1.25.4.0.bin
+File: cxgb4/t6fw-1.25.4.0.bin
+Link: cxgb4/t6fw.bin -> t6fw-1.25.4.0.bin
 File: cxgb4/aq1202_fw.cld
 File: cxgb4/bcm8483.bin
 File: cxgb4/configs/t4-config-default.txt
diff --git a/cxgb4/configs/t6-config-default.txt b/cxgb4/configs/t6-config-default.txt
index db281b68..b0145ab2 100644
--- a/cxgb4/configs/t6-config-default.txt
+++ b/cxgb4/configs/t6-config-default.txt
@@ -110,7 +110,8 @@
 	sge_dbq_timer = 3, 2, 1, 5, 7, 9, 12, 16
 
 	# enable TP_OUT_CONFIG.IPIDSPLITMODE
-	reg[0x7d04] = 0x00010000/0x00010000
+	# Set TP_OUT_CONFIG.CCplAckMode to get srtt/rttvar
+	reg[0x7d04] = 0x00012000/0x00012000
 
 	reg[0x7dc0] = 0x0e2f8849	# TP_SHIFT_CNT
 
@@ -200,6 +201,9 @@
 	hma_size = 92 			# Size (in MBs) of host memory expected
 	hma_regions = stag,pbl,rq	# What all regions to place in host memory
 
+	#enable bottleneck-bw congestion control mode
+	#ofld_flags = 4
+
 # Some "definitions" to make the rest of this a bit more readable.  We support
 # 4 ports, 3 functions (NIC, FCoE and iSCSI), scaling up to 8 "CPU Queue Sets"
 # per function per port ...
@@ -588,7 +592,7 @@
 
 [fini]
 	version = 0x1425001d
-	checksum = 0xbcf115d
+	checksum = 0xa1403d73
 
 # Total resources used by above allocations:
 #   Virtual Interfaces: 104
diff --git a/cxgb4/t4fw-1.24.17.0.bin b/cxgb4/t4fw-1.24.17.0.bin
deleted file mode 100644
index 5d9f051d..00000000
Binary files a/cxgb4/t4fw-1.24.17.0.bin and /dev/null differ
diff --git a/cxgb4/t4fw-1.25.4.0.bin b/cxgb4/t4fw-1.25.4.0.bin
new file mode 100644
index 00000000..9b61bfbf
Binary files /dev/null and b/cxgb4/t4fw-1.25.4.0.bin differ
diff --git a/cxgb4/t5fw-1.24.17.0.bin b/cxgb4/t5fw-1.24.17.0.bin
deleted file mode 100644
index 5b923ba6..00000000
Binary files a/cxgb4/t5fw-1.24.17.0.bin and /dev/null differ
diff --git a/cxgb4/t5fw-1.25.4.0.bin b/cxgb4/t5fw-1.25.4.0.bin
new file mode 100644
index 00000000..0e28b8aa
Binary files /dev/null and b/cxgb4/t5fw-1.25.4.0.bin differ
diff --git a/cxgb4/t6fw-1.24.17.0.bin b/cxgb4/t6fw-1.24.17.0.bin
deleted file mode 100644
index e7edc850..00000000
Binary files a/cxgb4/t6fw-1.24.17.0.bin and /dev/null differ
diff --git a/cxgb4/t6fw-1.25.4.0.bin b/cxgb4/t6fw-1.25.4.0.bin
new file mode 100644
index 00000000..c366eb29
Binary files /dev/null and b/cxgb4/t6fw-1.25.4.0.bin differ