Messages in this thread | | | Date | Wed, 27 Apr 2016 18:25:16 +0800 | From | Jisheng Zhang <> | Subject | Re: [RESEND PATCH v2 7/7] usb: xhci: plat: add vbus regulator control |
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Dear Mark,
On Wed, 27 Apr 2016 10:57:39 +0100 Mark Brown wrote:
> On Wed, Apr 27, 2016 at 08:37:20AM +0300, Felipe Balbi wrote: > > Jisheng Zhang <jszhang@marvell.com> writes: > > > > + vbus = devm_regulator_get(&pdev->dev, "vbus"); > > > devm_regulator_get_optional() ?? > > Does USB work without a VBUS? Unless the answer is yes then I'd expect > this to be just a normal regulator_get().
Per spec no. But the vbus may be transparent to SW on some platforms, so I think devm_regulator_get_optional() is better.
> > > > > > + if (PTR_ERR(vbus) == -ENODEV) { > > > + vbus = NULL; > > > + } else if (IS_ERR(vbus)) { > > > + ret = PTR_ERR(vbus); > > > + goto disable_clk; > > > + } else if (vbus) { > > > + ret = regulator_enable(vbus); > > > + if (ret) { > > > + dev_err(&pdev->dev, > > > + "failed to enable usb vbus regulator: %d\n", > > > + ret); > > > + goto disable_clk; > > > + } > > > + } > > This is all completely broken unless the supply is optional.
The supply is optional.
Thanks for your review, Jisheng
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