on 2024/8/22 21:19, Andy Shevchenko wrote:

On Thu, Aug 22, 2024 at 11:39:09AM +0800, Lei Liu wrote:

quoted

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().

...

quoted

-	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