[RFC PATCH] clk: fix clk_get_rate() always return ulong

[Julien Masson]

On Mon 29 Aug 2022 at 10:38, Simon Glass <sjg at chromium.org> wrote:

> Hi,
> 
> On Fri, 26 Aug 2022 at 08:00, Sean Anderson <seanga2 at gmail.com> wrote:
>>
>> On 8/26/22 6:31 AM, Julien Masson wrote:
>>> According to clk_ops struct definition, the callback `get_rate()`
>>> return current clock rate value as ulong.
>>> `clk_get_rate()` should handle the clock rate returned as ulong also.
>>>
>>> Otherwise we may have invalid/truncated clock rate value returned by
>>> `clk_get_rate()`.
>>>
>>> `log_ret` has also been removed since it use an `int` in the macro
>>> definition.
>>>
>>> Signed-off-by: Julien Masson <jmasson at baylibre.com>
>>> ---
>>>   drivers/clk/clk-uclass.c | 4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
>>> index b89c77bf79..446f7c49b8 100644
>>> --- a/drivers/clk/clk-uclass.c
>>> +++ b/drivers/clk/clk-uclass.c
>>> @@ -469,7 +469,7 @@ void clk_free(struct clk *clk)
>>>   ulong clk_get_rate(struct clk *clk)
>>>   {
>>>       const struct clk_ops *ops;
>>> -     int ret;
>>> +     ulong ret;
>>>
>>>       debug("%s(clk=%p)\n", __func__, clk);
>>>       if (!clk_valid(clk))
>>> @@ -481,7 +481,7 @@ ulong clk_get_rate(struct clk *clk)
>>>
>>>       ret = ops->get_rate(clk);
>>>       if (ret)
>>> -             return log_ret(ret);
> 
> How about:
> 
> if (IS_ERR(ret))
>    return log_ret(ret)
Maybe we can let the caller do this check ?

This is how we do for these functions: clk_round_rate and clk_set_rate

> 
>>> +             return ret;
>>>
>>>       return 0;
>>
>> This can just be return ret no if required.
Yes correct I can directly return the callback, I will change that in v2.

> 
> Yes, but it is nice to have the 'success' path clear and at the end.
hummm it's not clear to me if return 0 is considered as 'success' path.
I guess some drivers doesn't expect to get 0 from a clock ...

As I suggested previously maybe we can let the caller handle the value
returned by the callback ? (like clk_round_rate and clk_set_rate)

> 
>>
>>>   }
>>>
> 
> Regards,
> Simon

-- 
Julien Masson