This is a note to let you know that I've just added the patch titled
net: axienet: reduce default RX interrupt threshold to 1
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-axienet-reduce-default-rx-interrupt-threshold-to.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 16f685785a50da07c61dbba5ac9af1773bed8f4a
Author: Robert Hancock <robert.hancock@xxxxxxxxxx>
Date: Fri Mar 4 20:24:42 2022 -0600
net: axienet: reduce default RX interrupt threshold to 1
[ Upstream commit 40da5d680e02ca8d61237192db4b5833d3c9639f ]
Now that NAPI has been implemented, the hardware interrupt mitigation
mechanism is not needed to avoid excessive interrupt load in most cases.
Reduce the default RX interrupt threshold to 1 to reduce introduced
latency. This can be increased with ethtool if desired if some applications
still want to reduce interrupts.
Signed-off-by: Robert Hancock <robert.hancock@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: 5a6caa2cfabb ("net: xilinx: axienet: Fix packet counting")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h
index e8a210201f744..d2c17def082b4 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h
@@ -122,7 +122,7 @@
/* Default TX/RX Threshold and waitbound values for SGDMA mode */
#define XAXIDMA_DFT_TX_THRESHOLD 24
#define XAXIDMA_DFT_TX_WAITBOUND 254
-#define XAXIDMA_DFT_RX_THRESHOLD 24
+#define XAXIDMA_DFT_RX_THRESHOLD 1
#define XAXIDMA_DFT_RX_WAITBOUND 254
#define XAXIDMA_BD_CTRL_TXSOF_MASK 0x08000000 /* First tx packet */
