cpufreq on PandaBoard

Booting a PandaBoard with a recent kernel and devicetree appears to be a rather messy process. There are dozens of devicetree-related warnings spewed on boot (many pertaining to missing regulators). At the moment, however, I'm most interested in this,

cpufreq-cpu0 cpufreq-cpu0.0: no of_node; not parsing pinctrl DT cpu cpu0: dummy supplies not allowed
cpufreq_cpu0: failed to get cpu0 regulator: -19
cpufreq_cpu0: failed to get cpu0 clock: -2
cpufreq-cpu0: probe of cpufreq-cpu0.0 failed with error -2

What is the status of cpufreq on the PandaBoard? Is this expected to work?

More generally, if one wants a fairly recent kernel supporting the PandaBoard's hardware what kernel tree should be used? Is mainline not yet appropriate? Is linux-next preferred? Perhaps a ti-maintained tree?

Quoted 15 lines · Ben Gamari

Booting a PandaBoard with a recent kernel and devicetree appears to be a rather messy process. There are dozens of devicetree-related warnings spewed on boot (many pertaining to missing regulators). At the moment, however, I'm most interested in this,

cpufreq-cpu0 cpufreq-cpu0.0: no of_node; not parsing pinctrl DT cpu cpu0: dummy supplies not allowed
cpufreq_cpu0: failed to get cpu0 regulator: -19
cpufreq_cpu0: failed to get cpu0 clock: -2
cpufreq-cpu0: probe of cpufreq-cpu0.0 failed with error -2

What is the status of cpufreq on the PandaBoard? Is this expected to work?

Quoted 3 lines

More generally, if one wants a fairly recent kernel supporting the PandaBoard's hardware what kernel tree should be used? Is mainline not yet appropriate? Is linux-next preferred? Perhaps a ti-maintained tree?

for upstream: Wait for the clock nodes to get merged.. we are at v9 of discussion thread here[1].

for ti-maintained tree, you need to talk to TI support folks for appropriate kernel for your product line.

Quoted 20 lines · Nishanth Menon

Quoted 18 lines · Ben Gamari

Booting a PandaBoard with a recent kernel and devicetree appears to be a rather messy process. There are dozens of devicetree-related warnings spewed on boot (many pertaining to missing regulators). At the moment, however, I'm most interested in this,

cpufreq-cpu0 cpufreq-cpu0.0: no of_node; not parsing pinctrl DT cpu cpu0: dummy supplies not allowed
cpufreq_cpu0: failed to get cpu0 regulator: -19
cpufreq_cpu0: failed to get cpu0 clock: -2
cpufreq-cpu0: probe of cpufreq-cpu0.0 failed with error -2

What is the status of cpufreq on the PandaBoard? Is this expected to work?

More generally, if one wants a fairly recent kernel supporting the PandaBoard's hardware what kernel tree should be used? Is mainline not yet appropriate? Is linux-next preferred? Perhaps a ti-maintained tree?

Quoted 3 lines

for upstream: Wait for the clock nodes to get merged.. we are at v9 of discussion thread here[1].

I take it that the clock node work does not itself fix cpufreq? I've built the 3.12-dt-clks-v10-dev branch. On the bright side, it boots and appears to run just fine. Unfortunately, there isn't even a mention of cpufreq in the boot log.

I've seen your Google+ post[1] from May enumerating the steps to having working DVFS. It would be useful to post an update showing what has been merged, what is waiting for merge, and what is still in progress.

Quoted 4 lines

for ti-maintained tree, you need to talk to TI support folks for appropriate kernel for your product line.

I wasn't asking for official support, just wondering where work is currently happening.

Thanks for your help.

Cheers,

- Ben

[1] https://plus.google.com/112464029509057661457/posts/gvyZQcNieoq

Quoted 5 lines · Ben Gamari

I take it that the clock node work does not itself fix cpufreq? I've built the 3.12-dt-clks-v10-dev branch. On the bright side, it boots and appears to run just fine. Unfortunately, there isn't even a mention of cpufreq in the boot log.

You are probably picking up a branch that is yet to be posted :)... and I assume you know the risk of in-development patches ;)

- the branch looks to introduce purely clock nodes which patch [2] adds on to and makes cpufreq work as a start..

Quoted 4 lines

I've seen your Google+ post[1] from May enumerating the steps to having working DVFS. It would be useful to post an update showing what has been merged, what is waiting for merge, and what is still in progress.

We are still at "step 1 - get clock nodes" :(... and no, situation has not improved since May 2013 when I originally posted that G+ comment (and not because we have not been trying..).

Quoted 2 lines

I wasn't asking for official support, just wondering where work is currently happening.

they are happening here in linux-omap mailing list.. just that the changes are pretty fundamental and a lot of discussions have been taking place