On Mon, Nov 18, 2019 at 12:20:10PM +0000, Robin Murphy wrote:

On 18/11/2019 11:59 am, Mark Brown wrote:

quoted

On Sat, Nov 16, 2019 at 12:54:20PM +0000, Robin Murphy wrote:

quoted

Null checks are both cheaper and more readable than having !IS_ERR()
splattered everywhere.

quoted

-	if (IS_ERR(rockchip->vpcie3v3))
+	if (!rockchip->vpcie3v3)
  		return;
  	/*

@@ -611,6 +611,7 @@ static int rockchip_pcie_parse_host_dt(struct rockchip_pcie *rockchip)
  		if (PTR_ERR(rockchip->vpcie12v) != -ENODEV)
  			return PTR_ERR(rockchip->vpcie12v);
  		dev_info(dev, "no vpcie12v regulator found\n");
+		rockchip->vpcie12v = NULL;

According to the API NULL is a valid regulator.  We don't currently
actually do this but it's storing up surprises if you treat it as
invalid.

Ah, OK - I'd assumed NULL wasn't valid based on regulator_enable()
immediately dereferencing its argument without any checks. If we'd rather
not bake in that assumption then this patch can happily be ignored.

I'd suggest we drop this patch.

"IS_ERR(ptr)" is not the same as "!ptr", for values of ptr between 0 and
-4095 inclusive.

Regardless the effect of this patch with the regulator framework, I don't
think we want to create an example that others may follow.

Thanks,

Andrew Murray

Thanks,
Robin.

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