Messages in this thread | | | From | John Stultz <> | Date | Thu, 7 Nov 2019 14:23:20 -0800 | Subject | Re: [PATCH v4 9/9] usb: dwc3: Add host-mode as default support |
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On Tue, Oct 29, 2019 at 2:25 AM Felipe Balbi <balbi@kernel.org> wrote: > John Stultz <john.stultz@linaro.org> writes: > > diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c > > index 61d4fd8aead4..0e3466fe5ac4 100644 > > --- a/drivers/usb/dwc3/drd.c > > +++ b/drivers/usb/dwc3/drd.c > > @@ -489,7 +489,10 @@ static int dwc3_usb_role_switch_set(struct device *dev, enum usb_role role) > > mode = DWC3_GCTL_PRTCAP_DEVICE; > > break; > > default: > > - mode = DWC3_GCTL_PRTCAP_DEVICE; > > + if (dwc->role_switch_default_mode == USB_DR_MODE_HOST) > > + mode = DWC3_GCTL_PRTCAP_HOST; > > + else > > + mode = DWC3_GCTL_PRTCAP_DEVICE; > > break; > > } > > > > @@ -515,7 +518,10 @@ static enum usb_role dwc3_usb_role_switch_get(struct device *dev) > > role = dwc->current_otg_role; > > break; > > default: > > - role = USB_ROLE_DEVICE; > > + if (dwc->role_switch_default_mode == USB_DR_MODE_HOST) > > + role = USB_ROLE_HOST; > > look at this, we now have 3 different encodings for role which DWC3 > needs to understand. One is its own PRTCAP_DIR, then there USB_DR_MODE_* > and now USB_ROLE_*, can we make it so that we only have one private > encoding and one generic encoding?
And you left out the DWC3_OTG_ROLE_* set too!
So I agree it can be easy to muddle up. The enums are *almost* equivalent:
include/linux/usb/role.h: enum usb_role { USB_ROLE_NONE, USB_ROLE_HOST, USB_ROLE_DEVICE, };
include/linux/usb/otg.h: enum usb_dr_mode { USB_DR_MODE_UNKNOWN, USB_DR_MODE_HOST, USB_DR_MODE_PERIPHERAL, USB_DR_MODE_OTG, };
But both are widely used: $ git grep USB_ROLE_ | wc -l 123 $ git grep USB_DR_MODE_ | wc -l 190
So I'm not sure how easy it will be to condense down, since the usage is coming from different usb subsystems (otg and role switching) and I worry assuming them equivalent in just one driver may run into trouble eventually if the values diverge (ie someone adds USB_ROLE_BRICK or something).
Heikki/Greg: Any thoughts on this? Does it make sense to try to drop the usb_role enum and users and replace it with usb_dr_mode?
thanks -john
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