igb: Add DMA Coalescing feature to driver
This patch add DMA Coalescing which is a power-saving feature that
coalesces DMA writes in order to stay in a low-power state as much
as possible. Feature is disabled by default.
Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c
index df15a91..d976733 100644
--- a/drivers/net/igb/igb_ethtool.c
+++ b/drivers/net/igb/igb_ethtool.c
@@ -2009,6 +2009,12 @@
if ((adapter->flags & IGB_FLAG_QUEUE_PAIRS) && ec->tx_coalesce_usecs)
return -EINVAL;
+ /* If ITR is disabled, disable DMAC */
+ if (ec->rx_coalesce_usecs == 0) {
+ if (adapter->flags & IGB_FLAG_DMAC)
+ adapter->flags &= ~IGB_FLAG_DMAC;
+ }
+
/* convert to rate of irq's per second */
if (ec->rx_coalesce_usecs && ec->rx_coalesce_usecs <= 3)
adapter->rx_itr_setting = ec->rx_coalesce_usecs;