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/eth1394.c b/drivers/ieee1394/eth1394.c
index 30fa0d4..b2d2c4d 100644
--- a/drivers/ieee1394/eth1394.c
+++ b/drivers/ieee1394/eth1394.c
@@ -502,10 +502,8 @@
/* Determine speed limit */
for (i = 0; i < host->node_count; i++)
- if (max_speed > host->speed_map[NODEID_TO_NODE(host->node_id) *
- 64 + i])
- max_speed = host->speed_map[NODEID_TO_NODE(host->node_id) *
- 64 + i];
+ if (max_speed > host->speed[i])
+ max_speed = host->speed[i];
priv->bc_sspd = max_speed;
/* We'll use our maxpayload as the default mtu */