> Roland, should I submit a proper patch, or do you want
> to take care of this? (And thanks alot, too!)
Thanks for testing... I can take care of this -- I just added the
patches below to my tree (since as far as I can see, mlx4 would be
susceptible to the same bug):
commit 66547550601a706e2b958ea351b34d8dee066b18
Author: Roland Dreier <rolandd@cisco.com>
Date: Sat Oct 6 13:35:24 2007 -0700
IB/mthca: Use mmiowb() to avoid firmware commands getting jumbled up
Firmware commands are sent to the HCA by writing multiple words to a
command register block. Access to this block of registers is
serialized with a mutex. However, on large SGI systems, problems were
seen with multiple CPUs issuing FW commands at the same time, because
the writes to the register block may be reordered within the system
interconnect and reach the HCA in a different order than they were
issued (even with the mutex). Fix this by adding an mmiowb() before
dropping the mutex.
Tested-by: Arthur Kepner <akepner@sgi.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_cmd.c b/drivers/infiniband/hw/mthca/mthca_cmd.c
index acc9589..6966f94 100644
--- a/drivers/infiniband/hw/mthca/mthca_cmd.c
+++ b/drivers/infiniband/hw/mthca/mthca_cmd.c
@@ -290,6 +290,12 @@ static int mthca_cmd_post(struct mthca_dev *dev,
err = mthca_cmd_post_hcr(dev, in_param, out_param, in_modifier,
op_modifier, op, token, event);
+ /*
+ * Make sure that our HCR writes don't get mixed in with
+ * writes from another CPU starting a FW command.
+ */
+ mmiowb();
+
mutex_unlock(&dev->cmd.hcr_mutex);
return err;
}
commit 8c2348735c721eed6f08343eed851bfbec6e5a9a
Author: Roland Dreier <rolandd@cisco.com>
Date: Sat Oct 6 13:39:38 2007 -0700
mlx4_core: Use mmiowb() to avoid firmware commands getting jumbled up
Firmware commands are sent to the HCA by writing...
