Re: [PATCH 5/8] tty: mps2-uart: Use devm_clk_get_enabled() helpers

Lei Liu
2024-08-22T13:29:14Z

on 2024/8/22 21:19, Andy Shevchenko wrote:
> On Thu, Aug 22, 2024 at 11:39:09AM +0800, Lei Liu wrote:
>> The devm_clk_get_enabled() helpers:
>> - call devm_clk_get()
>> - call clk_prepare_enable() and register what is needed in order to
>> call clk_disable_unprepare() when needed, as a managed resource.
>>
>> This simplifies the code and avoids calls to clk_disable_unprepare().
> ...
>
>> - mps_port->clk = devm_clk_get(&pdev->dev, NULL);
>> + mps_port->clk = devm_clk_get_enabled(&pdev->dev, NULL);
>> if (IS_ERR(mps_port->clk))
>> return PTR_ERR(mps_port->clk);
>>
>> - ret = clk_prepare_enable(mps_port->clk);
>> - if (ret)
>> - return ret;
>> -
>> mps_port->port.uartclk = clk_get_rate(mps_port->clk);
>>
>> - clk_disable_unprepare(mps_port->clk);
> Your change is not equivalent. In case this clock is shared this may lead to
> run-time issues. Hence I don't think this patch is needed in this case.
> Instead, you may add a comment on top of devm_clk_get() to explain that we only
> need it be enabled to get clock rate in the probe.

Thank you for your suggestion. I will adopt your advice in the second
version of the patch and make no changes.

---
With Best Regards,

Lei Liu