Re: Turris Omnia firmware possibilities [Was: Re: led: hw-trigger, global brightness and multi-colored leds]

From: Uwe Kleine-KÃnig
Date: Tue Aug 14 2018 - 09:27:27 EST


Hello Tomas,

On 05/25/2018 04:02 PM, Tomas Hlavacek wrote:
>> Talking about firmware, I wonder if there is firmware supported needed
>> to solve
>> https://wiki.debian.org/InstallingDebianOn/TurrisOmnia#Power_Management
>> . Didn't look into that deeply yet and probably not high prio given that
>> normally the Turris Omnia will just run 7x24h.
>
> That's right, there is no power-down signalization from the CPU right
> now. Btw. is there any mechanism in kernel to signal over arbitrary
> bus (like I2C) that the host is shutting down and the power can/should
> be cut to CPU in N seconds?

I think there is no interface for "in N seconds" and currently the i2c
core isn't prepared to do such stuff "late" (i.e. when the system is
going down and irqs are already off). But there is some work ongoing to
address that:

https://marc.info/?l=linux-i2c&m=153419498527890&w=2

Best regards
Uwe

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