From: Roland Dreier <rolandd@cisco.com>
Date: Wed, 17 May 2006 14:48:07 +0000 (-0700)
Subject: IB/mthca: Make fw_cmd_doorbell default to 0
X-Git-Tag: v2.6.17-rc5~90^2~5
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1db76c14d215c8b26024dd532de3dcaf66ea30f7;p=linux-2.6

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@cisco.com>
---

diff --git a/drivers/infiniband/hw/mthca/mthca_cmd.c b/drivers/infiniband/hw/mthca/mthca_cmd.c
index 1985b5dfa4..798e13e14f 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)");