On Wed, Feb 10, 2021, at 1:23 AM, Pali Rohár wrote:
> On Tuesday 09 February 2021 18:07:41 nnet wrote:
> > On Tue, Feb 9, 2021, at 5:51 PM, nnet wrote:
> > > On Tue, Feb 9, 2021, at 5:31 PM, nnet wrote:
> > > > On Tue, Feb 9, 2021, at 3:26 PM, Marek Behún wrote:
> > > > > On Tue, 09 Feb 2021 15:16:45 -0800
> > > > > nnet <n...@fastmail.fm> wrote:
> > > > >
> > > > > > I've two of these and I've just swapped them (and re-pasted the
> > > > > > heat sinks).
> > > > > >
> > > > > > The second one ran under load for awhile and now has frozen as well.
> > > > > >
> > > > > > Under a moderate load `wget -O /dev/null <large.bin>` @X00Mbits
> > > > > > they are fine.
> > > > > >
> > > > > > Under a 1 min speed test of load ~200Mbits routed WireGuard they
> > > > > > freeze.
> > > > > >
> > > > > > They fine with both those workloads @1000_800.
> > > > > >
> > > > > > Perhaps it's heat? Unfortunately I don't have any numbers on that
> > > > > > ATM.
> > > > >
> > > > > Try disabling cpufreq in kernel completely, compile boot image at
> > > > > 1200 MHz. If it continues freezing, then I fear we can't help you with
> > > > > 1200 MHz :(
> > > >
> > > > cat
> > > > /sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies
> > > > 200000 300000 600000 1200000
> > > >
> > > > I'm not getting any freezes with 1.2GHz fixed after 20 minutes of load:
> > > >
> > > > echo 1200000 > /sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq
> > > >
> > > > Setting it back to min 200MHz I get a freeze within a minute:
> > > >
> > > > echo 200000 > /sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq
>
> Hello! Could you please enable userspace governor during kernel
> compilation?
>
> CONFIG_CPU_FREQ_GOV_USERSPACE=y
>
> It can be activated via command:
>
> echo userspace > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
>
> After that you can "force" CPU frequency to specific value, e.g.:
>
> echo 1000000 > /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed
>
> I need to know which switch (from --> to freq) cause this system hang.
>
> This patch series (via MIN_VOLT_MV_FOR_L0_L1_1GHZ) is fixing only
> switching from 500 MHz to 1000 MHz on 1 GHz variant. As only this switch
> is causing issue.
>
> I have used following simple bash script to check that switching between
> 500 MHz and 1 GHz is stable:
>
> while true; do
> echo 1000000 >
> /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed;
> echo 500000 >
> /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed;
> echo 1000000 >
> /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed;
> echo 500000 >
> /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed;
> done
echo userspace | tee /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
while true; do
echo 1200000 | tee /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed;
echo 600000 | tee /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed;
done
>> +#define MIN_VOLT_MV_FOR_L0_L1_1GHZ 1108
With 1108 I get a freeze within a minute. The last output to stdout is 600000.
With 1120 it takes a few minutes.
With any of 1225, 1155, 1132 the device doesn't freeze over the full 5 minute
load test.
I'm using ondemand now with the above at 1132 without issue so far.
>> Update the CPU voltage value for loads L0 and L1 accordingly when base
>> frequency is 1000 or 1200 MHz. The minimal value is updated from the
>> original 1.05V to 1.108V.
Perhaps similiar to how a minimum of 1108 mV is useful when shifting to 1GHz,
using a minimum of 1132 is useful when shifting to 1.2GHz.
> (of course on 1.2 GHz variant you need to adjust values as only
> following frequencies 200000 300000 600000 1200000 are supported)
>
> > > > > Marek
> > > > >
> > >
> > > > +#define MIN_VOLT_MV_FOR_L0_L1_1GHZ 1108
> > >
> > > Based on the below at boot time might an equivalent of the above need
> > > to be 1225 for 1.2GHz?
> > >
> > > 1200_750
> > > SVC REV: 5, CPU VDD voltage: 1.225V
> > >
> > > 1000_800
> > > SVC REV: 5, CPU VDD voltage: 1.108V
>
> This value is printed in WTMI avs.c by following code:
>
> shift = OTP_SVC_SPEED_1000_OFF;
> (OR)
> shift = OTP_SVC_SPEED_1200_OFF;
>
> vdd_otp = ((otp_data[OTP_DATA_SVC_SPEED_ID] >> shift) +
> AVS_VDD_BASE) & AVS_VDD_MASK;
> regval |= (vdd_otp << HIGH_VDD_LIMIT_OFF);
> regval |= (vdd_otp << LOW_VDD_LIMIT_OFF);
> printf("SVC REV: %d, CPU VDD voltage: %s\n", svc_rev,
> avis_dump[vdd_otp].desc);
>
> So voltage value is read from the OTP memory.
>
> But I do not know what this value means.
>
> > I did this for a quick test for 1.2GHz:
> >
> > +#define MIN_VOLT_MV_FOR_L0_L1_1GHZ 1225
> >
> > This is working well so far. Frequency is shifting up/down with load
> > applied/stopped.
>
