[U-Boot] [PATCH 0/8] Stop AXP from crashing when enabeling LDO3

[Olliver Schinagl]

Hey Jagan,

FYI,

I used the wrong e-mail address, I think it is still listed in some of 
the u-boot sources.

Olliver

On 01-03-17 15:06, Olliver Schinagl wrote:
> Hey Maxime, Jagan,
>
> On 01-03-17 14:00, Maxime Ripard wrote:
>> Hi Oliver,
>>
>> On Wed, Mar 01, 2017 at 01:52:16PM +0100, Olliver Schinagl wrote:
>>> Hi list,
>>>
>>> When powering up an AXP209, the default value for LDO3 output is
>>> enabled. This
>>> works fine. However if for whatever reason, LDO3 is disabled, for
>>> example by OS
>>> during reboot and u-boot enables LDO3 again, the PMIC shutsdown (without
>>> setting an interrupt) causing the board to hang. This behavior has
>>> been seen
>>> from Linux as well, u-boot disables LDO3 as a default value, the
>>> kernel enables
>>> it per its DTS, the kernel hangs as the PMIC gets shut down.
>>>
>>> The root cause is that some boards have to high capacitance on the
>>> LDO3 output
>>> port causing inrush currents exceeding the maximum of the AXP209.
>>>
>>> The fix is to turn on the LDO3 at the lowest possible voltage and
>>> then set the
>>> final voltage.
>>>
>>> If the capacitance is really big (due to a connected device for
>>> example) the
>>> AXP209 also features VRC, or Voltage Rate Control, which allows the
>>> voltage
>>> ramp up to be even slower.
>>>
>>> This patch series implements the above with a few tiny, cleanups I
>>> ran into
>>> underway.
>>>
>>> The initial discussion with some scope screenshots can be found in the
>>> linux-sunxi mailing list [0].
>>
>> If you don't CC the proper maintainers, no one is going to pick the
>> patches.
>
> Appologies, I did check the u-boot page, where sunxi is still listed as
> orphaned and the AXP stuff does not show up with the sunxi maintainers.
>
> @Jagan, do you wish for me to resend the series, or can you see them via
> the linux-sunxi list?
>
> Olliver
>
>>
>> Maxime
>>