ieee1394: write broadcast_channel only to select nodes (fixes device recognition)
Some old 1394-1995 SBP-2 bridges would hang if they received a broadcast write
request to BROADCAST_CHANNEL before the config ROM was read. Affected devices
include Datafab MD2-FW2 2.5" HDD and SmartDisk VST FWCDRW-V8 portable CD writer.
The write request is now directed to specific nodes instead of being broadcast
to all nodes at once, and it is only performed if a previous read request at
this register succeeded.
Fixes an old interoperability problem which was perceived as a 2.6.14-specific
regression: http://marc.theaimsgroup.com/?t=113190586800003
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jody McIntyre <scjody@modernduck.com>
(cherry picked from 61c7f775ca
commit)
This commit is contained in:
parent
48622b7bde
commit
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@ -1349,6 +1349,33 @@ static void nodemgr_update_pdrv(struct node_entry *ne)
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}
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/* Write the BROADCAST_CHANNEL as per IEEE1394a 8.3.2.3.11 and 8.4.2.3. This
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* seems like an optional service but in the end it is practically mandatory
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* as a consequence of these clauses.
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*
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* Note that we cannot do a broadcast write to all nodes at once because some
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* pre-1394a devices would hang. */
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static void nodemgr_irm_write_bc(struct node_entry *ne, int generation)
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{
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const u64 bc_addr = (CSR_REGISTER_BASE | CSR_BROADCAST_CHANNEL);
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quadlet_t bc_remote, bc_local;
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int ret;
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if (!ne->host->is_irm || ne->generation != generation ||
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ne->nodeid == ne->host->node_id)
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return;
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bc_local = cpu_to_be32(ne->host->csr.broadcast_channel);
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/* Check if the register is implemented and 1394a compliant. */
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ret = hpsb_read(ne->host, ne->nodeid, generation, bc_addr, &bc_remote,
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sizeof(bc_remote));
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if (!ret && bc_remote & cpu_to_be32(0x80000000) &&
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bc_remote != bc_local)
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hpsb_node_write(ne, bc_addr, &bc_local, sizeof(bc_local));
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}
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static void nodemgr_probe_ne(struct host_info *hi, struct node_entry *ne, int generation)
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{
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struct device *dev;
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@ -1360,6 +1387,8 @@ static void nodemgr_probe_ne(struct host_info *hi, struct node_entry *ne, int ge
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if (!dev)
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return;
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nodemgr_irm_write_bc(ne, generation);
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/* If "needs_probe", then this is either a new or changed node we
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* rescan totally. If the generation matches for an existing node
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* (one that existed prior to the bus reset) we send update calls
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@ -1431,9 +1460,7 @@ static int nodemgr_send_resume_packet(struct hpsb_host *host)
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return ret;
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}
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/* Because we are a 1394a-2000 compliant IRM, we need to inform all the other
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* nodes of the broadcast channel. (Really we're only setting the validity
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* bit). Other IRM responsibilities go in here as well. */
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/* Perform a few high-level IRM responsibilities. */
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static int nodemgr_do_irm_duties(struct hpsb_host *host, int cycles)
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{
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quadlet_t bc;
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@ -1442,13 +1469,8 @@ static int nodemgr_do_irm_duties(struct hpsb_host *host, int cycles)
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if (!host->is_irm || host->irm_id == (nodeid_t)-1)
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return 1;
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host->csr.broadcast_channel |= 0x40000000; /* set validity bit */
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bc = cpu_to_be32(host->csr.broadcast_channel);
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hpsb_write(host, LOCAL_BUS | ALL_NODES, get_hpsb_generation(host),
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(CSR_REGISTER_BASE | CSR_BROADCAST_CHANNEL),
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&bc, sizeof(quadlet_t));
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/* We are a 1394a-2000 compliant IRM. Set the validity bit. */
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host->csr.broadcast_channel |= 0x40000000;
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/* If there is no bus manager then we should set the root node's
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* force_root bit to promote bus stability per the 1394
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