[openib-general] Re: ib_mthca fails to load with old firmware

[Roland Dreier]

OK, I put this into my 2.6.17 branch:

diff-tree 1db76c14d215c8b26024dd532de3dcaf66ea30f7 (from 032ebf2620ef99a4fedaa0f77dc2272095ac5863)
Author: Roland Dreier <rolandd at cisco.com>
Date:   Wed May 17 07:48:07 2006 -0700

    IB/mthca: Make fw_cmd_doorbell default to 0
    
    Setting fw_cmd_doorbell allows FW command to be queued using posted
    writes instead of requiring polling on a "go" bit, so it should be a
    performance boost.  However, the option causes problems with at least
    some device/firmware combinations, so set the default to 0 until we
    understand what's going on better.
    
    Signed-off-by: Roland Dreier <rolandd at cisco.com>

diff --git a/drivers/infiniband/hw/mthca/mthca_cmd.c b/drivers/infiniband/hw/mthca/mthca_cmd.c
index 1985b5d..798e13e 100644
--- a/drivers/infiniband/hw/mthca/mthca_cmd.c
+++ b/drivers/infiniband/hw/mthca/mthca_cmd.c
@@ -182,7 +182,7 @@ struct mthca_cmd_context {
 	u8                status;
 };
 
-static int fw_cmd_doorbell = 1;
+static int fw_cmd_doorbell = 0;
 module_param(fw_cmd_doorbell, int, 0644);
 MODULE_PARM_DESC(fw_cmd_doorbell, "post FW commands through doorbell page if nonzero "
 		 "(and supported by FW)");