Re: tegra-devfreq hangs TK1 with R21.4 u-boot

Stephen Warren
2016-06-17T16:17:30Z

On 06/12/2016 11:31 AM, Martin Michlmayr wrote:
> * Shreshtha <shreshthakumar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> [2016-06-12 17:15]:
>>> I noticed that the Jetson TK1 hangs during boot (when/before mounting
>>> the SD disk) when CONFIG_ARM_TEGRA_DEVFREQ=y is set and when u-boot
>>> from R21.4 is used (2014.10-rc2).
>>
>> I cannot find CONFIG_ARM_TEGRA_DEVFREQ in r21.4 codeline. With default
>> "tegra12_defconfig", CONFIG_PM_DEVFREQ is getting enabled.
>>
>> Can you please share some more details about CONFIG_ARM_TEGRA_DEVFREQ, which
>> file it complies and if it is really present in code or pulled from other git.
>
> Sorry for not being clear. I'm talking about the mainline kernel from
> kernel.org:
> drivers/devfreq/Makefile:obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o
>
> Booting a mainline kernel with tegra-devfreq enabled will hang my machine
> during bootup when I use the u-boot from R21.4 (which I believe is the
> latest provided by NVIDIA).

Note that if you're booting a mainline kernel, there's no need to use
the L4T U-Boot release; a mainline U-Boot release should work just fine.
Or put another way, the "latest provided by NVIDIA" is actually mainline
U-Boot, unless you need to boot a downstream L4T kernel which has some
downstream-specific requirements.