From: Bruce Allan <bruce.w.allan@intel.com>
Date: Sat, 9 Aug 2008 01:35:51 +0000 (-0700)
Subject: e1000e: Set InterruptThrottleRate to default when invalid value used
X-Git-Tag: v2.6.27-rc4~39^2~48^2~21
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=2d06cad1a5ceb3b04dc9547e261ad4fcebf7433d;p=~emulex%2Finfiniband.git

e1000e: Set InterruptThrottleRate to default when invalid value used

During module load, seting the InterruptThrottleRate parameter to an
invalid value would result in the itr/itr_setting pair being set to
unexpected values which would result in poor performance.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
---

diff --git a/drivers/net/e1000e/param.c b/drivers/net/e1000e/param.c
index 8effc3107f9..b0499f27e5f 100644
--- a/drivers/net/e1000e/param.c
+++ b/drivers/net/e1000e/param.c
@@ -327,11 +327,26 @@ void __devinit e1000e_check_options(struct e1000_adapter *adapter)
 				e1000_validate_option(&adapter->itr, &opt,
 					adapter);
 				/*
-				 * save the setting, because the dynamic bits
-				 * change itr. clear the lower two bits
-				 * because they are used as control
+				 * Save the setting, because the dynamic bits
+				 * change itr.
 				 */
-				adapter->itr_setting = adapter->itr & ~3;
+				if (e1000_validate_option(&adapter->itr, &opt,
+							  adapter) &&
+				    (adapter->itr == 3)) {
+					/*
+					 * In case of invalid user value,
+					 * default to conservative mode.
+					 */
+					adapter->itr_setting = adapter->itr;
+					adapter->itr = 20000;
+				} else {
+					/*
+					 * Clear the lower two bits because
+					 * they are used as control.
+					 */
+					adapter->itr_setting =
+						adapter->itr & ~3;
+				}
 				break;
 			}
 		} else {