[PATCH v2 2/2] soc: amlogic: ee-pwrc: ensure driver state maches HW state

Jerome Brunet jbrunet at baylibre.com
Mon Sep 30 01:22:28 PDT 2019

On Fri 27 Sep 2019 at 08:37, Neil Armstrong <narmstrong at baylibre.com> wrote:

> On 26/09/2019 21:08, Kevin Hilman wrote:
>> Neil Armstrong <narmstrong at baylibre.com> writes:
>>> On 25/09/2019 23:35, Kevin Hilman wrote:
>>>> From: Kevin Hilman <khilman at baylibre.com>
>>>> During init, ensure that the driver on/off state as well as clock and
>>>> reset state matches the hardware state.  Do this by always calling the
>>>> drivers 'on' function, and then callling the 'off' function if the
>>>> HW state was initially detected as off.
>> [...]
>>> I don't see what you are trying to solve except simplifying the code.
>> Simplifying the code is a worthwhile goal on its own, but that's not the
>> only thing I'm tring to accomplish.
> I still find it ugly to power_on a domain to power it off right afterwards.
> The issue is with the CCF enable handling which is not in sync with the
> HW, if you boot with an already enabled clock, it won't be marked enabled
> in CCF, and it's clearly bad when you want to have a fine-tuned gate state
> handling.

CCF should disable unused clock so, in theory, you should not have to
call enable() then disable() to get things in sync.

I suppose the clock in question has the flag CLK_IGNORE_UNUSED (one of
the gates) ?

If the CLK_INGORE_UNUSED is becoming a problem, it would be better to
fix the clock tree rather than adding quirks in consumers.

More information about the linux-amlogic mailing list