10robinho
Posts: 44
Joined: Thu Feb 28, 2013 7:42 pm

Difference between DWCOTG and DWC2

Fri Mar 31, 2017 8:18 am

Hello,

I can't find good answer about this online.
What is the difference in DWCOTG and DWC2 drivers?

I see both of them work on RPI3 but haven't tested them much.
Is DWC2 newer or somehow better?
I remember those dwc_otg configuration parameters few years ago until it become quite stable.
I never saw anything introducing dwc2 or explaining what is it's role, except that it's used for RPI Zero (in device tree).

Does anyone know something deeper about it?

gregeric
Posts: 1509
Joined: Mon Nov 28, 2011 10:08 am

Re: Difference between DWCOTG and DWC2

Fri Mar 31, 2017 11:08 am

dwc_otg is the driver that has been heavily patched to squeeze most performance & function in host mode on the Pi: the fiq stuff etc. So heavily patched that, despite the name, it only does host mode & not OTG.

dwc2 is an upstream driver which can do the OTG host/gadget flip dictated by OTG_SENSE. In host mode performance will pale cf dwc_otg, hence it's only recommended for gadget mode.

10robinho
Posts: 44
Joined: Thu Feb 28, 2013 7:42 pm

Re: Difference between DWCOTG and DWC2

Fri Mar 31, 2017 1:12 pm

gregeric wrote:dwc_otg is the driver that has been heavily patched to squeeze most performance & function in host mode on the Pi: the fiq stuff etc. So heavily patched that, despite the name, it only does host mode & not OTG.

dwc2 is an upstream driver which can do the OTG host/gadget flip dictated by OTG_SENSE. In host mode performance will pale cf dwc_otg, hence it's only recommended for gadget mode.
Thank you!

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