From: nnet <nnet@fastmail.fm>
To: "Pali Rohár" <pali@kernel.org>
Cc: "Marek Behún" <kabel@kernel.org>,
andrew@lunn.ch, luka.perkov@sartura.hr, sboyd@kernel.org,
gregory.clement@bootlin.com, a.heider@gmail.com,
linux-kernel@vger.kernel.org, vladimir.vid@sartura.hr,
mturquette@baylibre.com, rmk+kernel@armlinux.org.uk,
tmn505@gmail.com, gerald@gk2.net, miquel.raynal@bootlin.com,
kostap@marvell.com, linux-clk@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH mvebu v2 00/10] Armada 37xx: Fix cpufreq changing base CPU speed to 800 MHz from 1000 MHz
Date: Wed, 10 Feb 2021 09:34:07 -0800 [thread overview]
Message-ID: <d6971325-af71-4f71-91c2-7b661804c022@www.fastmail.com> (raw)
In-Reply-To: <20210210092339.qy6wwuq6qr5m2ozr@pali>
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 <nnet@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.
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-02-10 17:35 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <d59ba191-43db-4b7b-b201-62a60ca752c0@www.fastmail.com>
2021-02-09 21:33 ` [PATCH mvebu v2 00/10] Armada 37xx: Fix cpufreq changing base CPU speed to 800 MHz from 1000 MHz Pali Rohár
2021-02-09 21:45 ` nnet
2021-02-09 22:42 ` Pali Rohár
2021-02-09 22:52 ` nnet
2021-02-09 22:56 ` Pali Rohár
2021-02-09 23:16 ` nnet
2021-02-09 23:26 ` Marek Behún
2021-02-10 1:31 ` nnet
2021-02-10 1:51 ` nnet
2021-02-10 2:07 ` nnet
2021-02-10 9:23 ` Pali Rohár
2021-02-10 17:34 ` nnet [this message]
2021-02-10 18:03 ` Pali Rohár
2021-02-10 19:08 ` nnet
2021-02-10 19:18 ` Marek Behún
2021-02-11 19:55 ` Pali Rohár
2021-02-11 20:22 ` nnet
2021-02-11 23:44 ` Pali Rohár
2021-02-12 0:41 ` nnet
2021-02-13 10:01 ` Pali Rohár
2021-02-13 18:30 ` nnet
2021-02-14 12:33 ` Pali Rohár
2021-02-16 5:48 ` nnet
2021-02-16 10:41 ` Pali Rohár
2021-02-16 16:27 ` nnet
2021-02-19 19:33 ` Pali Rohár
2021-02-22 3:17 ` nnet
2021-02-22 9:51 ` Pali Rohár
2021-02-22 16:36 ` nnet
2021-02-22 16:40 ` Philip Soares
2021-02-10 2:12 ` Marek Behún
2021-01-14 12:40 Pali Rohár
2021-02-01 14:35 ` Tomasz Maciej Nowak
2021-02-03 19:29 ` Anders Trier Olesen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d6971325-af71-4f71-91c2-7b661804c022@www.fastmail.com \
--to=nnet@fastmail.fm \
--cc=a.heider@gmail.com \
--cc=andrew@lunn.ch \
--cc=gerald@gk2.net \
--cc=gregory.clement@bootlin.com \
--cc=kabel@kernel.org \
--cc=kostap@marvell.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luka.perkov@sartura.hr \
--cc=miquel.raynal@bootlin.com \
--cc=mturquette@baylibre.com \
--cc=pali@kernel.org \
--cc=rmk+kernel@armlinux.org.uk \
--cc=sboyd@kernel.org \
--cc=tmn505@gmail.com \
--cc=vladimir.vid@sartura.hr \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).