Re: [PATCH v4 9/9] usb: chipidea: add support to the generic PHY framework in ChipIdea

[Antoine Tenart <antoine.tenart@free-electrons.com>]

Peter,

On Thu, Sep 11, 2014 at 08:54:47AM +0800, Peter Chen wrote:
> On Wed, Sep 03, 2014 at 09:40:40AM +0200, Antoine Tenart wrote:
> > @@ -595,23 +639,27 @@ static int ci_hdrc_probe(struct platform_device *pdev)
> >  		return -ENODEV;
> >  	}
> >  
> > -	if (ci->platdata->usb_phy)
> > +	if (ci->platdata->phy)
> > +		ci->phy = ci->platdata->phy;
> > +	else if (ci->platdata->usb_phy)
> >  		ci->usb_phy = ci->platdata->usb_phy;
> >  	else
> > -		ci->usb_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
> > +		ci->phy = devm_phy_get(dev, "usb-phy");
> >  
> > -	if (IS_ERR(ci->usb_phy)) {
> > -		ret = PTR_ERR(ci->usb_phy);
> > +	if (IS_ERR(ci->phy) || (ci->phy == NULL && ci->usb_phy == NULL)) {
> >  		/*
> >  		 * if -ENXIO is returned, it means PHY layer wasn't
> >  		 * enabled, so it makes no sense to return -EPROBE_DEFER
> >  		 * in that case, since no PHY driver will ever probe.
> >  		 */
> > -		if (ret == -ENXIO)
> > -			return ret;
> > +		if (PTR_ERR(ci->phy) == -ENXIO)
> > +			return -ENXIO;
> >  
> > -		dev_err(dev, "no usb2 phy configured\n");
> > -		return -EPROBE_DEFER;
> > +		ci->usb_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
> > +		if (IS_ERR(ci->usb_phy)) {
> > +			dev_err(dev, "no usb2 phy configured\n");
> > +			return -EPROBE_DEFER;
> > +		}
> >  	}
> 
> Sorry, I can't accept this change, why devm_usb_get_phy(dev, USB_PHY_TYPE_USB2)
> is put at error path? Since current get PHY operation is a little complicated,
> we may have a dedicate function to do it, dwc3 driver is a good example.

It's not the error path, it's the case when there is no PHY from the
generic PHY framework available. Getting an USB PHY is a fallback
solution.

I agree we can move this to a dedicated function. But even if doing so,
we'll have to test ci->phy first.

Or do you have something else in mind?

> > diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c
> > index 5a7ea93011dd..999e9d683d7a 100644
> > --- a/drivers/usb/chipidea/debug.c
> > +++ b/drivers/usb/chipidea/debug.c
> > @@ -219,7 +219,8 @@ static int ci_otg_show(struct seq_file *s, void *unused)
> >  	fsm = &ci->fsm;
> >  
> >  	/* ------ State ----- */
> > -		usb_otg_state_string(ci->usb_phy->otg.state));
> > +	seq_printf(s, "OTG state: %s\n\n",
> > +		   usb_otg_state_string(ci->otg.state));
> 
> Again, rebase error?

Yes, sorry about that. This will be fixed in the next version of this
series.

Antoine

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