Re: [PATCH v3 0/4] clk: st: New always-on clock domain

From: Robert Jarzmik
Date: Fri Feb 27 2015 - 16:37:24 EST


Lee Jones <lee.jones@xxxxxxxxxx> writes:

> v2 => v3:
> - Ensure DT actually reflects h/w
> - i.e. Nodes should not contain a mishmash of different IP
> blocks, but should identify related h/w. In the current
> example we use interconnects
> - Change naming from clkdomain to clk-always-on
> - Place "do not abuse" warning in documentation
>
> v1 => v2:
> - Turned the ST specific driver into a generic one
>
> Hardware can have a bunch of clocks which must not be turned off.
> If drivers a) fail to obtain a reference to any of these or b) give
> up a previously obtained reference during suspend, the common clk
> framework will attempt to turn them off and the hardware will
> subsequently die. The only way to recover from this failure is to
> restart.
>
> To avoid either of these two scenarios from catastrophically
> disabling the running system we have implemented a clock domain
> where clocks are consumed and references are taken, thus preventing
> them from being shut down by the framework.

Hi Lee,

I wonder why there is a need for a new clock when CLK_IGNORE_UNUSED does
exist. What is the usecase that is covered by this patchset which is not used by
CLK_IGNORE_UNUSED clock flag ?

And if that reason exists, I'd like to find it in the commit message.

Cheers.

--
Robert
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/