Re: [PATCH 2/3] clk: Introduce 'critical-clocks' property

[Stephen Boyd <sboyd@kernel.org>]

Quoting Marek Vasut (2022-03-09 12:54:35)
> On 2/21/22 01:58, Marek Vasut wrote:
> > On 2/17/22 23:23, Stephen Boyd wrote:
> > 
> >> I see that there isn't any more 'clock-critical' in the kernel's dts so
> >> I wonder if we would be able to get rid of that function or at least
> >> hollow it out and see if anyone complains. Either way, what is the
> >> actual problem trying to be solved? If the crystal oscillator isn't used
> >> anywhere in the kernel why are we registering it with the clk framework?
> > 
> > The problem is the other way around -- the SoC clock IPs often have a 
> > couple of general purpose clock routed to various SoC IO pins, those 
> > clock can be used for any purpose, and those are already registered with 
> > kernel clock framework. Some devices save on BoM and use those general 
> > purpose clock to supply clock networks which are otherwise not 
> > interacting with the kernel, like some CPLD for example. Since from the 
> > kernel point of view, those clock are unused, the kernel can turn those 
> > clock OFF and that will make the entire device fail.
> > 
> > So this critical-clocks property permits marking clock which must not 
> > ever be turned OFF accordingly.
> 
> How can we proceed here ?

Why are we registering the clks with the framework on device that are
saving on BoM and using them outside of the kernel. What is the use of
kernel memory for struct clk_core that aren't ever used?