[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>
diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 7355580..8a23fb5 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -835,11 +835,16 @@
 
 	/* 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;