[net-next PATCH v3 4/4] net: stmmac: increase TX coalesce timer to 5ms

Christian Marangi
2023-10-14T09:30:48Z

Commit 8fce33317023 ("net: stmmac: Rework coalesce timer and fix
multi-queue races") decreased the TX coalesce timer from 40ms to 1ms.

This caused some performance regression on some target (regression was
reported at least on ipq806x) in the order of 600mbps dropping from
gigabit handling to only 200mbps.

The problem was identified in the TX timer getting armed too much time.
While this was fixed and improved in another commit, performance can be
improved even further by increasing the timer delay a bit moving from
1ms to 5ms.

The value is a good balance between battery saving by prevending too
much interrupt to be generated and permitting good performance for
internet oriented devices.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
drivers/net/ethernet/stmicro/stmmac/common.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 1e996c29043d..e3f650e88f82 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -293,7 +293,7 @@ struct stmmac_safety_stats {
#define MIN_DMA_RIWT 0x10
#define DEF_DMA_RIWT 0xa0
/* Tx coalesce parameters */
-#define STMMAC_COAL_TX_TIMER 1000
+#define STMMAC_COAL_TX_TIMER 5000
#define STMMAC_MAX_COAL_TX_TICK 100000
#define STMMAC_TX_MAX_FRAMES 256
#define STMMAC_TX_FRAMES 25
--
2.40.1