--- linux-2.6-64/drivers/parisc/sba_iommu.c	2004-11-06 14:43:52.000000000 -0800
+++ linux-2.6-32/drivers/parisc/sba_iommu.c	2004-11-08 22:19:09.914745816 -0800
@@ -1675,18 +1675,38 @@
 	if (!is_pdc_pat()) {
 		/* Shutdown the USB controller on Astro-based workstations.
 		** Once we reprogram the IOMMU, the next DMA performed by
-		** USB will HPMC the box.
+		** USB will HPMC the box. USB is only enabled if a
+		** keyboard is present and found.
+		**
+		** With serial console, j6k v5.0 firmware says:
+		**   mem_kbd hpa 0xfee003f8 sba 0x0 pad 0x0 cl_class 0x7
 		*/
-		pdc_io_reset_devices();
+		if (PAGE0->mem_kbd.cl_class == CL_KEYBD) {
+			pdc_io_reset_devices();
+		}
 
-		/*
-		** XXX May need something more sophisticated to deal
-		**     with DMA from LAN. Maybe use page zero boot device
-		**     as a handle to talk to PDC about which device to
-		**     shutdown. This also needs to work for is_pdc_pat(). 
-		*/
 	}
 
+
+#if 0
+printk("sba_hw_init(): mem_boot 0x%x 0x%x 0x%x 0x%x\n", PAGE0->mem_boot.hpa,
+	PAGE0->mem_boot.spa, PAGE0->mem_boot.pad, PAGE0->mem_boot.cl_class);
+
+	/*
+	** Need to deal with DMA from LAN.
+	**	Maybe use page zero boot device as a handle to talk
+	**	to PDC about which device to shutdown.
+	**
+	** Netbooting, j6k v5.0 firmware says:
+	** 	mem_boot hpa 0xf4008000 sba 0x0 pad 0x0 cl_class 0x1002
+	** ARGH! invalid class.
+	*/
+	if ((PAGE0->mem_boot.cl_class != CL_RANDOM)
+		&& (PAGE0->mem_boot.cl_class != CL_SEQU)) {
+			pdc_io_reset();
+	}
+#endif
+
 	if (!IS_PLUTO(sba_dev->iodc)) {
 		ioc_ctl = READ_REG(sba_dev->sba_hpa+IOC_CTRL);
 		DBG_INIT("%s() hpa 0x%lx ioc_ctl 0x%Lx ->",