From: Sameeh Jubran <sameehj@amazon.com>
Date: Wed, 1 May 2019 16:47:08 +0300
Subject: net: ena: improve latency by disabling adaptive interrupt moderation
by default
Patch-mainline: v5.2-rc1
Git-commit: 78cb421d185cfb4fcea94e7c3ff6e6ea77bb8c11
References: bsc#1138879 bsc#1139020 bsc#1139021
Adaptive interrupt moderation was erroneously enabled by default
in the driver.
In case the device supports adaptive interrupt moderation it will
be automatically used, which may potentially increase latency.
The adaptive moderation can be enabled from ethtool command in
case the feature is supported by the device.
Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Guy Tzalik <gtzalik@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/amazon/ena/ena_com.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -2801,7 +2801,11 @@ int ena_com_init_interrupt_moderation(st
/* if moderation is supported by device we set adaptive moderation */
delay_resolution = get_resp.u.intr_moderation.intr_delay_resolution;
ena_com_update_intr_delay_resolution(ena_dev, delay_resolution);
- ena_com_enable_adaptive_moderation(ena_dev);
+
+ /* Disable adaptive moderation by default - can be enabled from
+ * ethtool
+ */
+ ena_com_disable_adaptive_moderation(ena_dev);
return 0;
err: