ieee1394: support for slow links or slow 1394b phy ports
Add support for the following types of hardware:
+ nodes that have a link speed < PHY speed
+ 1394b PHYs that are less than S800 capable
+ 1394b/1394a adapter cable between two 1394b PHYs
Also, S1600 and S3200 are now supported if IEEE1394_SPEED_MAX is raised.
A probing function is added to nodemgr's config ROM fetching routine
which adjusts the allowable speed if an access problem was encountered.
Pros and Cons of the approach:
+ minimum code footprint to support this less widely used hardware
+ nearly no overhead for unaffected hardware
- ineffective before nodemgr began to read the ROM of affected nodes
- ineffective if ieee1394 is loaded with disable_nodemgr=1
The speed map CSRs which are published to the bus are not touched by the
patch.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Hakan Ardo <hakan@debian.org>
Cc: Calculex <linux@calculex.com>
Cc: Robert J. Kosinski <robk@cmcherald.com>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
diff --git a/drivers/ieee1394/ieee1394_core.c b/drivers/ieee1394/ieee1394_core.c
index be6854e..c83e2b8 100644
--- a/drivers/ieee1394/ieee1394_core.c
+++ b/drivers/ieee1394/ieee1394_core.c
@@ -285,9 +285,9 @@
static void build_speed_map(struct hpsb_host *host, int nodecount)
{
- u8 speedcap[nodecount];
u8 cldcnt[nodecount];
u8 *map = host->speed_map;
+ u8 *speedcap = host->speed;
struct selfid *sid;
struct ext_selfid *esid;
int i, j, n;
@@ -354,6 +354,11 @@
}
}
}
+
+ /* assume maximum speed for 1394b PHYs, nodemgr will correct it */
+ for (n = 0; n < nodecount; n++)
+ if (speedcap[n] == 3)
+ speedcap[n] = IEEE1394_SPEED_MAX;
}
@@ -554,11 +559,10 @@
return 0;
}
- if (packet->type == hpsb_async && packet->node_id != ALL_NODES) {
+ if (packet->type == hpsb_async &&
+ NODEID_TO_NODE(packet->node_id) != ALL_NODES)
packet->speed_code =
- host->speed_map[NODEID_TO_NODE(host->node_id) * 64
- + NODEID_TO_NODE(packet->node_id)];
- }
+ host->speed[NODEID_TO_NODE(packet->node_id)];
dump_packet("send packet", packet->header, packet->header_size, packet->speed_code);