[PATCH] ohci1394, sbp2: fix "scsi_add_device failed" with PL-3507 based devices

Re-enable posted writes for status FIFO.

Besides bringing back a very minor bandwidth tweak from Linux 2.6.15.x
and older, this also fixes an interoperability regression since 2.6.16:

   http://bugzilla.kernel.org/show_bug.cgi?id=6356
   (sbp2: scsi_add_device failed. IEEE1394 HD is not working anymore.)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Vanei Heidemann <linux@javanei.com.br>
Tested-by: Martin Putzlocher <mputzi@gmx.de> (chip type unconfirmed)
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/ieee1394/ohci1394.c

@@ -553,7 +553,7 @@ static void ohci_initialize(struct ti_ohci *ohci)
 	 * register content.
 	 * To actually enable physical responses is the job of our interrupt
 	 * handler which programs the physical request filter. */
-	reg_write(ohci, OHCI1394_PhyUpperBound, 0xffff0000);
+	reg_write(ohci, OHCI1394_PhyUpperBound, 0x01000000);
 
 	DBGMSG("physUpperBoundOffset=%08x",
 	       reg_read(ohci, OHCI1394_PhyUpperBound));

drivers/ieee1394/sbp2.c

@@ -835,11 +835,16 @@ static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud
 
 	/* Register the status FIFO address range. We could use the same FIFO
 	 * for targets at different nodes. However we need different FIFOs per
-	 * target in order to support multi-unit devices. */
+	 * target in order to support multi-unit devices.
+	 * The FIFO is located out of the local host controller's physical range
+	 * but, if possible, within the posted write area. Status writes will
+	 * then be performed as unified transactions. This slightly reduces
+	 * bandwidth usage, and some Prolific based devices seem to require it.
+	 */
 	scsi_id->status_fifo_addr = hpsb_allocate_and_register_addrspace(
 			&sbp2_highlevel, ud->ne->host, &sbp2_ops,
 			sizeof(struct sbp2_status_block), sizeof(quadlet_t),
-			~0ULL, ~0ULL);
+			0x010000000000ULL, CSR1212_ALL_SPACE_END);
 	if (!scsi_id->status_fifo_addr) {
 		SBP2_ERR("failed to allocate status FIFO address range");
 		goto failed_alloc;