[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>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 73555806c483..8a23fb54c693 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/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;