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Date:      Sat, 27 Feb 2021 13:52:57 -0800
From:      Mark Millard <marklmi@yahoo.com>
To:        Mike Karels <mike@karels.net>
Cc:        freebsd-arm@freebsd.org, manu@freebsd.org
Subject:   Re: cpufreq driver stopped working on RPI4
Message-ID:  <7D6CCA5B-F24D-48CF-893C-18AD73417E4E@yahoo.com>
In-Reply-To: <202102271742.11RHg4r2012120@mail.karels.net>
References:  <202102271742.11RHg4r2012120@mail.karels.net>

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> On 2021-Feb-27, at 09:42, Mike Karels <mike at karels.net> wrote:
>=20
> Following up on my previous post (below): I tried the ALPHA1 kernel on
> a BETA3 system on the RPI4, and it fails to attach the cpufreq driver
> as well.  So it appears that the problem is in the dtb, etc, not the
> kernel.
>=20
> It would be nice to get this fixed before the 13.0 release.  Without
> the cpufreq driver, the CPU is stuck at a low clock rate.

In config.txt for an RPi4B I use (as an example, you
could use other figures):

over_voltage=3D6
arm_freq=3D2000
arm_freq_min=3D2000
sdram_freq_min=3D3200

and in /etc/sysctl.conf I have:

# The u-boot'ed RPi4B does not seem to automatically
# adjust from 600MHz, so do so manually. Presumes
# config.txt does over_voltage=3D6 and arm_freq=3D2000 .
# NOTE: without an appropriate over_voltage a
# dev.cpu.0.freq=3D2000 will crash the RPi4B on the
# spot.
dev.cpu.0.freq=3D2000

Overall this gives a constant faster frequency
for the CPU (and the sdram). (I have a good power
supply context for this.)

You may or may not be able to tolerate the constant
status for frequencies. But there is this alternative
to cpufreq use.


> 		Mike
>=20
>> To: freebsd-arm@freebsd.org
>> From: Mike Karels <mike@karels.net>
>> Reply-to: mike@karels.net
>> Subject: cpufreq driver stopped working on RPI4
>> Date: Sun, 21 Feb 2021 14:43:27 -0600
>=20
>> I upgraded an older (original) RPI4, 4 GB, to 13.0-BETA3, and merged =
my
>> previous rc.conf including powerd.  Powerd fails to start now, saying
>> that there is no cpufreq(4) support.  Sure enough, dmesg has the =
following
>> relevant lines:
>=20
>>    bcm2835_cpufreq0: <CPU Frequency Control> on cpu0
>>    bcm2835_cpufreq0: Unable to find firmware device
>>    device_attach: bcm2835_cpufreq0 attach returned 6
>>    armv8crypto0: CPU lacks AES instructionsbcm2835_cpufreq0: <CPU =
Frequency Control> on cpu0
>>    bcm2835_cpufreq0: Unable to find firmware device
>>    device_attach: bcm2835_cpufreq0 attach returned 6
>=20
>> (Yes, armv8crypto is missing a newline.)
>=20
>> I checked the most recent system I had on the shelf, which was =
13.0-ALPHA1.
>> It has this:
>=20
>>    bcm2835_firmware0: <BCM2835 Firmware> on simplebus0
>>    ofw_clkbus1: <OFW clocks bus> on bcm2835_firmware0
>>    gpio0: <Raspberry Pi Firmware GPIO controller> on =
bcm2835_firmware0
>>    bcm2835_cpufreq0: <CPU Frequency Control> on cpu0
>>    bcm2835_cpufreq0: ARM 600MHz, Core 200MHz, SDRAM 400MHz, Turbo OFF
>=20
>> Does anyone know what changed to cause this?  Was it the FDT update?
>=20

=3D=3D=3D
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)




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