Hi Jisheng,
 
 On sam., sept. 30 2017, Jisheng Zhang [off-list ref] wrote:

Hi Thomas,

On Sat, 30 Sep 2017 08:07:10 +0200 Thomas Petazzoni wrote:

quoted

Hello,

On Sat, 30 Sep 2017 10:41:09 +0800, Jisheng Zhang wrote:

quoted

quoted

+	priv->axi_clk = devm_clk_get(&pdev->dev, "axi");
+	if (IS_ERR(priv->axi_clk)) {
+		err = PTR_ERR(priv->axi_clk);
+		if (err == -EPROBE_DEFER)
+			goto err_clk;
+		priv->axi_clk = NULL;    

IMHO, this assignment could be removed. What do you think?  

No, because if the clock is not present in the Device Tree,
priv->axi_clk will contain an error code encoded as a pointer, so
priv->axi_clk will not be NULL. Hence the rest of the code that will

FWICT, the clk_disable_unprepare() could also check whether the clk
is err, am I wrong?

You're right, I've jsut checked it.
So I will remove it to have a smaller fix.

Thanks,

Gregory

quoted

operate on this clock will believe there is a valid clock pointed by
priv->axi_clk. So we really want to reset it to NULL when there was an
error getting the clock.

Best regards,

Thomas

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com