From 18f12e6f69a9597c13d2d18f5eb661f4549331e4 Mon Sep 17 00:00:00 2001 From: Koen Vandeputte Date: Tue, 12 Sep 2023 15:38:27 +0200 Subject: [PATCH] ipq40xx: switch to performance governor by default MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Doing a simple ping to my device shows this: 64 bytes from 10.0.253.101: icmp_seq=1 ttl=64 time=2.00 ms 64 bytes from 10.0.253.101: icmp_seq=2 ttl=64 time=2.02 ms 64 bytes from 10.0.253.101: icmp_seq=3 ttl=64 time=1.68 ms 64 bytes from 10.0.253.101: icmp_seq=4 ttl=64 time=1.91 ms 64 bytes from 10.0.253.101: icmp_seq=5 ttl=64 time=1.92 ms 64 bytes from 10.0.253.101: icmp_seq=6 ttl=64 time=2.04 ms Some users even report higher values on older kernels: 64 bytes from 192.168.1.10: seq=0 ttl=64 time=0.612 ms 64 bytes from 192.168.1.10: seq=1 ttl=64 time=2.852 ms 64 bytes from 192.168.1.10: seq=2 ttl=64 time=2.719 ms 64 bytes from 192.168.1.10: seq=3 ttl=64 time=2.741 ms 64 bytes from 192.168.1.10: seq=4 ttl=64 time=2.808 ms The problem is that the governor is set to Ondemand, which causes the CPU to clock all the way down to 48MHz in some cases. Switching to performance governor: 64 bytes from 10.0.253.101: icmp_seq=1 ttl=64 time=0.528 ms 64 bytes from 10.0.253.101: icmp_seq=2 ttl=64 time=0.561 ms 64 bytes from 10.0.253.101: icmp_seq=3 ttl=64 time=0.633 ms 64 bytes from 10.0.253.101: icmp_seq=4 ttl=64 time=0.526 ms In theory, using the Performance governor should increase power draw, but it looks like it really does not matter for this soc. Using a calibrated precision DC power supply (cpu idle): Ondemand 24.00V * 0.134A = 3.216 Watts 48.00V * 0.096A = 4.608 Watts Performance 24.00V * 0.135A = 3.240 Watts 48.00V * 0.096A = 4.608 Watts Let's simply switch to the Performance governor by default to fix the general jittery behaviour on devices using this soc. Tested on: MikroTik wAP ac Fixes: #13649 Reviewed-by: Robert Marko Reviewed-by: Thibaut VARÈNE Signed-off-by: Koen Vandeputte (cherry picked from commit b8e52852bd62236a2a84663b4592d221ebc64cb4) --- target/linux/ipq40xx/config-5.4 | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/target/linux/ipq40xx/config-5.4 b/target/linux/ipq40xx/config-5.4 index 0fb49355cb..43f885d12f 100644 --- a/target/linux/ipq40xx/config-5.4 +++ b/target/linux/ipq40xx/config-5.4 @@ -66,8 +66,8 @@ CONFIG_CPU_COPY_V6=y CONFIG_CPU_CP15=y CONFIG_CPU_CP15_MMU=y CONFIG_CPU_FREQ=y -CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y -# CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set +# CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set +CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_ATTR_SET=y CONFIG_CPU_FREQ_GOV_COMMON=y # CONFIG_CPU_FREQ_GOV_CONSERVATIVE is not set