cpufreq driver stopped working on RPI4

Mike Karels mike at karels.net
Sat Feb 27 22:28:54 UTC 2021


Thanks, Mark.  Meanwhile, I just tested BETA4; much to my surprise,
the cpufreq driver configured again.  I didn't notice a relevant change,
but it is working...

		Mike

Mark wrote:
> > On 2021-Feb-27, at 09:42, Mike Karels <mike at karels.net> wrote:
> > 
> > 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.
> > 
> > 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=6
> arm_freq=2000
> arm_freq_min=2000
> sdram_freq_min=3200

> 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=6 and arm_freq=2000 .
> # NOTE: without an appropriate over_voltage a
> # dev.cpu.0.freq=2000 will crash the RPi4B on the
> # spot.
> dev.cpu.0.freq=2000

> 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
> > 
> >> To: freebsd-arm at freebsd.org
> >> From: Mike Karels <mike at karels.net>
> >> Reply-to: mike at karels.net
> >> Subject: cpufreq driver stopped working on RPI4
> >> Date: Sun, 21 Feb 2021 14:43:27 -0600
> > 
> >> 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:
> > 
> >>    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
> > 
> >> (Yes, armv8crypto is missing a newline.)
> > 
> >> I checked the most recent system I had on the shelf, which was 13.0-ALPHA1.
> >> It has this:
> > 
> >>    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
> > 
> >> Does anyone know what changed to cause this?  Was it the FDT update?
> > 

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


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