On 02.07.19 13:33, Abel Vesa wrote: > On 19-07-02 08:47:19, Martin Kepplinger wrote: >> On 28.06.19 10:54, Abel Vesa wrote: >>> On 19-06-23 13:47:26, Martin Kepplinger wrote: >>>> On 10.06.19 14:13, Abel Vesa wrote: >>>>> This is another alternative for the RFC: >>>>> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.org%2Flkml%2F2019%2F3%2F27%2F545&data=02%7C01%7Cabel.vesa%40nxp.com%7Ccfc582f9977d479b7dda08d6feb9258a%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636976468485275045&sdata=L%2Byn29%2FBS3KMjm9eCPBTZBTl30PmZywSjIj11bMQw5c%3D&reserved=0 >>>>> >>>>> This new workaround proposal is a little bit more hacky but more contained >>>>> since everything is done within the irq-imx-gpcv2 driver. >>>>> >>>>> Basically, it 'hijacks' the registered gic_raise_softirq __smp_cross_call >>>>> handler and registers instead a wrapper which calls in the 'hijacked' >>>>> handler, after that calling into EL3 which will take care of the actual >>>>> wake up. This time, instead of expanding the PSCI ABI, we use a new vendor SIP. >>>>> >>>>> I also have the patches ready for TF-A but I'll hold on to them until I see if >>>>> this has a chance of getting in. >>>> >>>> Let's leave out of the picture for now, how generally applicable and >>>> mergable your changes are. I'd like to reproduce what you do and test >>>> cpuidle on imx8mq: >>>> >>>> When applying your changes here and the corresponding ATF changes ( >>>> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fabelvesa%2Farm-trusted-firmware%2Ftree%2Fimx8mq-err11171&data=02%7C01%7Cabel.vesa%40nxp.com%7Ccfc582f9977d479b7dda08d6feb9258a%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636976468485275045&sdata=VT3duSl70DNxcY8Ev4FFrHlWoOjkcckeM8BgxrSkr8A%3D&reserved=0 if >>>> I got that right) I don't yet see any difference in the SoC heating up >>>> under zero load. __cpu_do_idle() is called about every 1ms (without your >>>> changes, that was even more often but I'm not yet sure if that means >>>> anything). >>> >>> You will most probably not see any change in the SoC temp since the cpuidle >>> only touches the A53s. There are way many more IPs in the SoC that could >>> heat it up. If you want some real numbers you'll have to measure the power >>> consumtion on VDD_ARM rail. If you don't want to go through that much trouble >>> you can use the idlestat tool to measure the times each A53 speends in cpu-sleep >>> state. >>> >>>> >>>> What I also see is that I get about 10x more "arch_timer" (int.3, GICv3) >>>> interrupts than without your changes. >> >> >> thanks for getting back at me here. This is run on the imx8mq >> librem5-devkit with your wakeup-workaround applied. Typical measurements >> under zero load look like this: >> >> sudo idlestat --trace -f /tmp/mytrace -t 10 -p -c -w >> Log is 10.000395 secs long with 31194 events >> ------------------------------------------------------------------------ >> | C-state | min | max | avg | total | hits | over | under | >> ------------------------------------------------------------------------ >> | clusterA | >> ------------------------------------------------------------------------ >> | WFI | 14us | 3.99ms | 3.90ms | 9.93s | 2543 | 0 | 0 | >> ------------------------------------------------------------------------ >> | cpu0 | >> ------------------------------------------------------------------------ >> | WFI | 14us | 3.99ms | 3.89ms | 9.96s | 2561 | 0 | 0 | >> ------------------------------------------------------------------------ >> ... >> > > I don't see the cpu-sleep state at all in your idlestat log. Maybe the cpuidle > isn't enabled. Or probably the workaround itself is not applied. You'll have > to look into that. > > Here is how it looks like with the workaround enabled: > > Log is 10.001685 secs long with 1175 events > -------------------------------------------------------------------------------- > | C-state | min | max | avg | total | hits | over | under | > -------------------------------------------------------------------------------- > | clusterA | > -------------------------------------------------------------------------------- > | WFI | 2us | 50.04ms | 29.63ms | 9.99s | 337 | 0 | 0 | > -------------------------------------------------------------------------------- > | cpu0 | > -------------------------------------------------------------------------------- > | WFI | 11us | 50.04ms | 40.44ms | 9.62s | 238 | 0 | 219 | > | cpu-sleep | 537us | 50.58ms | 14.11ms | 366.94ms | 26 | 7 | 0 | > -------------------------------------------------------------------------------- > | cpu1 | > -------------------------------------------------------------------------------- > | WFI | 11us | 539.04ms | 93.20ms | 5.78s | 62 | 0 | 38 | > | cpu-sleep | 536us | 607.90ms | 183.38ms | 4.22s | 23 | 12 | 0 | > -------------------------------------------------------------------------------- > | cpu2 | > -------------------------------------------------------------------------------- > | WFI | 41us | 265.99ms | 17.51ms | 332.66ms | 19 | 0 | 11 | > | cpu-sleep | 568us | 6.56s | 1.38s | 9.67s | 7 | 2 | 0 | > -------------------------------------------------------------------------------- > | cpu3 | > -------------------------------------------------------------------------------- > | WFI | 7.94ms | 881.50ms | 367.81ms | 1.10s | 3 | 0 | 3 | > | cpu-sleep | 549us | 2.02s | 808.72ms | 8.90s | 11 | 1 | 0 | > -------------------------------------------------------------------------------- > > You can see that the cpu2 was once for 6.56 seconds (out of 10s) in cpu-sleep. > So I run this ATF tree https://github.com/abelvesa/arm-trusted-firmware/tree/imx8mq-err11171 and, on top of "v5.2-rc7" I have your commits ("irqchip: irq-imx-gpcv2: Add workaround for i.MX8MQ ERR11171") and ("arm64: dts: imx8mq: Add idle states and gpcv2 wake_request broken property") applied. Then simply enabled CONFIG_ARM_CPUIDLE. (I also use the "imx-cpufreq-dt" driver, but this should be unrelated here). I do see the possible cpuidle states: /sys/devices/system/cpu/cpu0/cpuidle$ cat state*/name WFI cpu-sleep but idlestat doesn't see it or it is (thus) never used. Do you know a needed change I might be missing? thanks again, martin
