target/linux/generic/backport-6.1/771-v6.7-03-net-stmmac-increase-TX-coalesce-timer-to-5ms.patch

   1 From 039550960a2235cfe2dfaa773df9f98f8da31a0c Mon Sep 17 00:00:00 2001
   2 From: Christian Marangi <ansuelsmth@gmail.com>
   3 Date: Wed, 18 Oct 2023 14:35:50 +0200
   4 Subject: [PATCH 3/3] net: stmmac: increase TX coalesce timer to 5ms
   5
   6 Commit 8fce33317023 ("net: stmmac: Rework coalesce timer and fix
   7 multi-queue races") decreased the TX coalesce timer from 40ms to 1ms.
   8
   9 This caused some performance regression on some target (regression was
  10 reported at least on ipq806x) in the order of 600mbps dropping from
  11 gigabit handling to only 200mbps.
  12
  13 The problem was identified in the TX timer getting armed too much time.
  14 While this was fixed and improved in another commit, performance can be
  15 improved even further by increasing the timer delay a bit moving from
  16 1ms to 5ms.
  17
  18 The value is a good balance between battery saving by prevending too
  19 much interrupt to be generated and permitting good performance for
  20 internet oriented devices.
  21
  22 Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
  23 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
  24 ---
  25  drivers/net/ethernet/stmicro/stmmac/common.h | 2 +-
  26  1 file changed, 1 insertion(+), 1 deletion(-)
  27
  28 --- a/drivers/net/ethernet/stmicro/stmmac/common.h
  29 +++ b/drivers/net/ethernet/stmicro/stmmac/common.h
  30 @@ -287,7 +287,7 @@ struct stmmac_safety_stats {
  31  #define MIN_DMA_RIWT           0x10
  32  #define DEF_DMA_RIWT           0xa0
  33  /* Tx coalesce parameters */
  34 -#define STMMAC_COAL_TX_TIMER   1000
  35 +#define STMMAC_COAL_TX_TIMER   5000
  36  #define STMMAC_MAX_COAL_TX_TICK        100000
  37  #define STMMAC_TX_MAX_FRAMES   256
  38  #define STMMAC_TX_FRAMES       25