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

["Vaittinen, Matti" <Matti.Vaittinen@fi.rohmeurope.com>]

On 2/16/22 18:52, Marek Vasut wrote:
> On 2/16/22 13:06, Vaittinen, Matti wrote:
> 
> Hi,
> 
> [...]
> 
>>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>>> index 8de6a22498e70..1e1686fa76e01 100644
>>> --- a/drivers/clk/clk.c
>>> +++ b/drivers/clk/clk.c
>>> @@ -3872,6 +3872,45 @@ static void clk_core_free_parent_map(struct 
>>> clk_core *core)
>>>        kfree(core->parents);
>>>    }
>>> +static void
>>> +__clk_register_critical_clock(struct device_node *np, struct 
>>> clk_core *core,
>>> +                  struct clk_hw *hw)
>>> +{
>>> +    struct of_phandle_args clkspec;
>>> +    u32 clksize, clktotal;
>>> +    int ret, i, index;
>>> +
>>> +    if (!np)
>>> +        return;
>>> +
>>> +    if (!core->ops->match_clkspec)
>>> +        return;
>>> +
>>> +    if (of_property_read_u32(np, "#clock-cells", &clksize))
>>> +        return;
>>> +
>>> +    /* Clock node with #clock-cells = <0> uses critical-clocks; */
>>> +    if (clksize == 0) {
>>> +        if (of_property_read_bool(np, "critical-clocks") &&
>>> +            !core->ops->match_clkspec(hw, &clkspec))
>>
>> I think this is never true as there is
>> if (!core->ops->match_clkspec)
>>     return;
>>
>> above.
> 
> If the driver implements match_clkspec() callback, then the callback 
> gets used here to determine whether the clock match this clkspec.

/me feels _utterly_ stupid.

Of course :) I somehow completely misread the code. Sorry for the noise!

>> Anyways, seeing you added a dummy bd71837_match_clkspec in a follow-up
>> patch for BD71837 - which has only single clock - I wonder if there is a
>> way to omit that dummy callback in controllers which really provide only
>> one clock?
> 
> Yes, I think we can omit the match_clkspec call for clock controllers 
> with clock-cells == 0 altogether.

That would mean you could probably drop the bd718x7 driver patch, right?


Best Regards
	-- Matti

-- 
The Linux Kernel guy at ROHM Semiconductors

Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

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