Re: [STLinux Kernel] [PATCH 0/4] clk: Provide support for always-on clocks

From: Gabriel Fernandez
Date: Thu Apr 02 2015 - 05:45:23 EST

Hi Peter, Lee,

With these series as they are, we need 'clk_ignore_unused' on
sthi407-b2120.dts and stih418-b2199.dts.

We have to modificate stih407-clock.dtsi and stih418-clock.dtsi in same way.


On 2 April 2015 at 10:12, Peter Griffin <peter.griffin@xxxxxxxxxx> wrote:
> Hi Lee,
> On Fri, 27 Feb 2015, Lee Jones wrote:
>> Some hardware contains bunches of clocks which must never 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
>> disable them and a platform can fail irrecoverably as a
>> result. Usually the only way to recover from these failures
>> is to reboot.
>> To avoid either of these two scenarios from catastrophically
>> disabling an otherwise perfectly healthy running system,
>> clocks can be identified as always-on using this property
>> from inside a clocksource's node. The CLK_IGNORE_UNUSED
>> flag will be applied to each clock instance named in this
>> property, thus preventing them from being shut down by the
>> framework.
> Great stuff.
> One minor comment is that assuming this works on stih407 and stih410
> to the extent that the platform can now boot without clk_ignore_unused
> kenel parameter then you should have an additional patch to remove
> clk_ignore_unused from the default bootargs in stih407-b2120.dts and
> stih410-b2120.dts files.
> Maxime - Is it possible for you to test this series on stih418-b2199 as
> a well? As it could most likely also be removed from stih418-b2199.dts file
> to, but neither Lee or myself have the hardware to test.
> Apart from that, for the series: -
> Acked-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
> regards,
> Peter.
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