[PATCH 1/2] dt-bindings: usb: generic-ehci: document ignore-oc flag

Alan Stern stern at rowland.harvard.edu
Tue Feb 23 11:09:32 EST 2021


On Tue, Feb 23, 2021 at 05:04:57PM +0100, Álvaro Fernández Rojas wrote:
> Hi Alan,
> 
> > El 23 feb 2021, a las 16:54, Alan Stern <stern at rowland.harvard.edu> escribió:
> > 
> > On Tue, Feb 23, 2021 at 04:50:04PM +0100, Álvaro Fernández Rojas wrote:
> >> Over-current reporting isn't supported on some platforms such as bcm63xx.
> >> These devices will incorrectly report over-current if this flag isn't properly
> >> activated.
> >> 
> >> Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
> >> ---
> >> Documentation/devicetree/bindings/usb/generic-ehci.yaml | 5 +++++
> >> 1 file changed, 5 insertions(+)
> >> 
> >> diff --git a/Documentation/devicetree/bindings/usb/generic-ehci.yaml b/Documentation/devicetree/bindings/usb/generic-ehci.yaml
> >> index cf83f2d9afac..294bbf02399e 100644
> >> --- a/Documentation/devicetree/bindings/usb/generic-ehci.yaml
> >> +++ b/Documentation/devicetree/bindings/usb/generic-ehci.yaml
> >> @@ -117,6 +117,11 @@ properties:
> >>       Set this flag if EHCI has a Transaction Translator built into
> >>       the root hub.
> >> 
> >> +  ignore-oc:
> >> +    $ref: /schemas/types.yaml#/definitions/flag
> >> +    description:
> >> +      Set this flag for HCDs without over-current reporting support.
> > 
> > This is not a good description of a device property.  DT entries are 
> > supposed to described the hardware, not talk about how to use it.
> 
> Any suggestions on a proper description?
> 
> > 
> > When you say that the bcm63xx doesn't support over-current reporting, 
> > what exactly do you mean?  Do you mean that sometimes the hardware turns 
> > on the over-current bit when an over-current isn't actually present?  Or 
> > do you mean something else?
> 
> Yes, the hardware turns on the over-current bit with no over-current present.

Okay, in that case the property should be named something like 
"spurious_oc", and the description should say something like:

	Set this flag to indicate that the hardware sometimes turns on 
	the OC bit when an over-current isn't actually present.

Alan Stern



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