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authorJoachim Fenkes <fenkes@de.ibm.com>2007-11-30 16:19:41 -0800
committerRoland Dreier <rolandd@cisco.com>2007-11-30 16:19:41 -0800
commitb1812582ba94b5f377d5d3cec7646cc17d84e733 (patch)
treeb176268f3b565171bc223fac2296f4982b12bbc1 /drivers/infiniband
parent1401b53acc0328d96bacb2a3393d2852699df96b (diff)
IB/ehca: Fix static rate if path faster than link
The formula would yield -1 if the path is faster than the link, which is wrong in a bad way (max throttling). Clamp to 0, which is the correct value. Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/hw/ehca/ehca_av.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/infiniband/hw/ehca/ehca_av.c b/drivers/infiniband/hw/ehca/ehca_av.c
index 453eb995c1d..f7782c882ab 100644
--- a/drivers/infiniband/hw/ehca/ehca_av.c
+++ b/drivers/infiniband/hw/ehca/ehca_av.c
@@ -76,8 +76,12 @@ int ehca_calc_ipd(struct ehca_shca *shca, int port,
link = ib_width_enum_to_int(pa.active_width) * pa.active_speed;
- /* IPD = round((link / path) - 1) */
- *ipd = ((link + (path >> 1)) / path) - 1;
+ if (path >= link)
+ /* no need to throttle if path faster than link */
+ *ipd = 0;
+ else
+ /* IPD = round((link / path) - 1) */
+ *ipd = ((link + (path >> 1)) / path) - 1;
return 0;
}