Messages in this thread | | | Date | Mon, 23 May 2011 10:20:49 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [PATCH v12 7/8] usb: Adding SuperSpeed support to dummy_hcd |
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On Mon, 23 May 2011, Felipe Balbi wrote:
> > > > +module_param_named(is_super_speed, mod_data.is_super_speed, bool, > > > > +S_IRUGO); MODULE_PARM_DESC(is_super_speed, "true to simulate > > > > +SuperSpeed connection"); > > > > > > you shouldn't need this. You should always enable SuperSpeed for this > > > driver. > > > > You mean I don't need the module parameter? IMO it's the best way to enable > > HS connection. If driver->speed=USB_SPEED_SUPER than dummy_hcd will try to > > enumerate the device on the SS root hub and if the gadget didn't provide SS > > descriptors - it will fail. Just as it happened before. Finding out from > > then it should hand the device over to the hs_hcd ;-) Meaning it would > disconnect the device, switch to hs_hcd and reconnect :-)
No. That doesn't happen with real devices, so there's no reason dummy-hcd should do it.
> > dummy_hcd that the enumeration failed is very complicated (if even possible) > > and I'm not sure that is the right thing to do... If you connect a real > > device over SS port to xHCI and the device doesn't provide SS descriptors - > > the enumeration fails and it's ok. But if you connect the same device to a > > HS port - it should work properly. This is what I tried to simulate with > > this parameter. > > it doesn't just fails, it gives the device over to the shared_hcd :-)
It does not. xhci-hcd does not keep track of whether or not enumeration succeeds, and it doesn't do anything special when enumeration fails.
Alan Stern
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