[PATCH v5 2/5] ARM: imx6: gpc: Add PU power domain for GPU/VPU

[Philipp Zabel]

Am Mittwoch, den 05.03.2014, 19:05 +0800 schrieb Shawn Guo:
> On Wed, Mar 05, 2014 at 11:05:24AM +0100, Philipp Zabel wrote:
> > > > +static int imx_gpc_probe(struct platform_device *pdev)
> > > > +{
> > > > +	struct regulator *pu_reg;
> > > > +	struct clk *clk;
> > > > +	bool is_off;
> > > > +	int ret, i;
> > > > +
> > > > +	pu_reg = devm_regulator_get(&pdev->dev, "pu");
> > > > +	if (IS_ERR(pu_reg)) {
> > > > +		ret = PTR_ERR(pu_reg);
> > > > +		dev_err(&pdev->dev, "failed to get pu regulator: %d\n", ret);
> > > > +		return ret;
> > > > +	}
> > > > +
> > > > +	/* The regulator is initially enabled */
> > > > +	ret = regulator_enable(pu_reg);
> > > > +	if (ret < 0) {
> > > > +		dev_err(&pdev->dev, "failed to enable pu regulator: %d\n", ret);
> > > > +		return ret;
> > > > +	}
> > > > +	imx6q_pu_domain.base.of_node = pdev->dev.of_node;
> > > 
> > > How does this work with !CONFIG_PM build?
> > 
> > Since I removed the regulator-always-on property from the PU regulator
> > in the device tree, if CONFIG_PM is disabled, we have to request and
> > enable pu_reg here. Otherwise the regulator framework will helpfully
> > turn it off (imx6q-cpufreq never enables pu_reg).
> > With the PU regulator disabled, the system would hang as soon as the
> > CODA VPU or one of the Vivante GPU cores is accessed if !CONFIG_PM.
> 
> Sorry, I should have been more specific.  My question is how stuff like
> imx6q_pu_domain are available for !CONFIG_PM build, since they are only
> defined in #ifdef CONFIG_PM right above imx_gpc_probe().

Ouch, I misread the quoted context. Yes, everything starting from
imx6q_pu_domain.base.of_node = pdev->dev.of_node;
needs to be #ifdef CONFIG_PM.

regards
Philipp