Subject: [PATCH v4 07/12] usb: chipidea: add a usb2 driver for ci13xxx

From: [email-masked] (Antoine Tenart)
Date: Thu, 11 Sep 2014 17:31:19 +0200

Peter,

On Thu, Sep 11, 2014 at 09:07:10AM +0800, Peter Chen wrote:
> On Wed, Sep 03, 2014 at 09:48:26AM +0200, Antoine Tenart wrote:
> > +
> > +static int ci_hdrc_usb2_dt_probe(struct device *dev,
> > +				 struct ci_hdrc_platform_data *ci_pdata)
> > +{
> > +	ci_pdata->phy = of_phy_get(dev->of_node, 0);
> > +	if (IS_ERR(ci_pdata->phy)) {
> > +		if (PTR_ERR(ci_pdata->phy) == -EPROBE_DEFER)
> > +			return -EPROBE_DEFER;
> > +
> > +		/* PHY is optional */
> > +		ci_pdata->phy = NULL;
> > +	}
> > +
> > +	return 0;
> > +}
> 
> You may also need to consider usb_phy case.

Don't we try using the generic PHY framework for new drivers?

Since there is no need for supporting an usb_phy case I don't think we
have to consider this case yet. And no doing so could encourage people
to add PHY drivers to the common PHY framework.

> > +
> > +	if (dev->of_node) {
> > +		ret = ci_hdrc_usb2_dt_probe(dev, ci_pdata);
> > +		if (ret)
> > +			return ret;
> > +	} else {
> > +		ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> > +		if (ret)
> > +			return ret;
> > +	}
> 
> You may need to do clk_disable_unprepare for above error cases.

Sure, I'll fix that.

> > +
> > +	ci_pdata->name = dev_name(&pdev->dev);
> > +
> > +	priv->ci_pdev = ci_hdrc_add_device(dev, pdev->resource,
> > +					   pdev->num_resources, ci_pdata);
> > +	if (IS_ERR(priv->ci_pdev)) {
> > +		ret = PTR_ERR(priv->ci_pdev);
> > +		if (ret != -EPROBE_DEFER)
> > +			dev_err(dev,
> > +				"failed to register ci_hdrc platform device: %d\n",
> > +				ret);
> 
> Why you don't want the error message for deferral probe?

A driver can return an EPROBE_DEFER error and still probe successfully
later. This would be confusing to have this kind of error message in
this case. And when a driver returns -EPROBE_DEFER, there is an error
message already.

Antoine

-- 
Antoine T?nart, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com