Re: [PATCH 08/32] riscv: Fix kernel time_init()

Damien Le Moal
2020-11-13T08:23:56Z

On 2020/11/13 17:11, Stephen Boyd wrote:
> Quoting Damien Le Moal (2020-11-12 23:57:19)
>> On 2020/11/13 16:53, Stephen Boyd wrote:
>>>
>>> Yes it's fine. Just the commit text reads as "If of_clk_init() is not
>>> called in time_init() then nothing works" which is true but made me
>>> wonder if it was because it needed to be super early or not. The commit
>>> text could be a little clearer here.
>>
>> OK. I will clarify the commit message in V2. Working on it now.
>
> Thanks!
>
>>
>>> We don't have any good solution for a fallback to call of_clk_init()
>>> somewhere later. I do wonder if we should generalize this though and
>>> call of_clk_init() from start_kernel() directly via some Kconfig that
>>> architectures select if they need it for their timer and then move it to
>>> an initcall if architectures don't select the config. Or throw it into
>>> the of_platform_default_populate_init() hook if the architecture doesn't
>>> need to call it early.
>>
>> This last idea seems reasonable and probably the easiest. And I think it could
>> be done unconditionally even if the arch calls of_clk_init() early as the
>> already populated clock provider nodes would not be initialized again.
>>
>
> Also of_clk_init() is for the CLK_OF_DECLARE() users and if they can
> wait to platform bus population time then they could be converted to
> regular old platform device drivers. Maybe the problem is the clk driver
> you're using is only using CLK_OF_DECLARE() and not registering a
> platform driver?

Yep, correct, that is what I did. SO yes, indeed, if I where to use a regular
platform_driver, then the of_clk_init() change would not be needed.

For the clock driver, I followed the pattern used by most other drivers with the
majority I think using CLK_OF_DECLARE(). I did see some using the platform
driver declaration though.

I could spend time trying to figure out if I can get away without using
CLK_OF_DECLARE(), but since I think other riscv board clock driver are arriving,
we may as well keep that of_clk_init() change, no ?

--
Damien Le Moal
Western Digital Research