diff options
Diffstat (limited to 'drivers/ieee1394/sbp2.c')
| -rw-r--r-- | drivers/ieee1394/sbp2.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c index 73555806c48..8a23fb54c69 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; |