The formula would yield -1 for this, which is wrong in a bad way (max
throttling). Clamp to 0, which is the correct value.

Signed-off-by: Joachim Fenkes <[EMAIL PROTECTED]>
---

This fixes another regression introduced in rc3.
Please review and apply for 2.6.24-rc4. Thanks!

 drivers/infiniband/hw/ehca/ehca_av.c |    8 ++++++--
 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 453eb99..f7782c8 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;
 }
-- 
1.5.2



_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev

Reply via email to