diff --git a/src/southbridge/nvidia/ck804/chip.h b/src/southbridge/nvidia/ck804/chip.h
index a9b18fb021..4c8d7b10bc 100644
--- a/src/southbridge/nvidia/ck804/chip.h
+++ b/src/southbridge/nvidia/ck804/chip.h
@@ -1,10 +1,11 @@
 #ifndef CK804_CHIP_H
 #define CK804_CHIP_H
 
-struct southbridge_nvidia_ck804_config 
+struct southbridge_nvidia_ck804_config
 {
-        unsigned int ide0_enable : 1;
-        unsigned int ide1_enable : 1;
+	unsigned int usb1_hc_reset : 1;
+	unsigned int ide0_enable : 1;
+	unsigned int ide1_enable : 1;
 	unsigned int sata0_enable : 1;
 	unsigned int sata1_enable : 1;
 	unsigned long nic_rom_address;
diff --git a/src/southbridge/nvidia/ck804/ck804_usb.c b/src/southbridge/nvidia/ck804/ck804_usb.c
index a839b7e338..d0b686abbc 100644
--- a/src/southbridge/nvidia/ck804/ck804_usb.c
+++ b/src/southbridge/nvidia/ck804/ck804_usb.c
@@ -9,9 +9,22 @@
 #include <device/pci_ops.h>
 #include "ck804.h"
 
+static void usb1_init(struct device *dev) {
+	struct southbridge_nvidia_ck804_config const * conf=dev->chip_info;
+	if (conf->usb1_hc_reset) {
+		//Somehow the warm reset does not really resets the USB controller.
+		//Later, during boot, when the Bus Master bit is set, the USB
+		//controller trashes the memory, causing weird misbehavior.
+		//Was detected on Sun Ultra40, where mptable was damaged.
+		uint32_t bar0=pci_read_config32(dev,0x10);
+		uint32_t* regs=(uint32_t*)(bar0&~0xfff);
+		regs[2]|=1;	//OHCI USB HCCommandStatus Register, HostControllerReset bit
+	}
+}
+
 static void lpci_set_subsystem(device_t dev, unsigned vendor, unsigned device)
-{       
-        pci_write_config32(dev, 0x40, 
+{
+        pci_write_config32(dev, 0x40,
                 ((device & 0xffff) << 16) | (vendor & 0xffff));
 }
 static struct pci_operations lops_pci = {
@@ -22,7 +35,7 @@ static struct device_operations usb_ops  = {
 	.read_resources   = pci_dev_read_resources,
 	.set_resources    = pci_dev_set_resources,
 	.enable_resources = pci_dev_enable_resources,
-	.init             = 0,
+	.init             = usb1_init,
 //	.enable           = ck804_enable,
 	.scan_bus         = 0,
 	.ops_pci          = &lops_pci,