Messages in this thread | | | From | "Tanya Brokhman" <> | Subject | RE: [PATCH v12 7/8] usb: Adding SuperSpeed support to dummy_hcd | Date | Mon, 23 May 2011 11:18:53 +0300 |
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> > > > + > > > > +static struct dummy_hcd_module_parameters mod_data = { > > > > + .is_super_speed = false > > > > +}; > > > > +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 :-)
Yes this will be the best solution :) But as I said, the enumeration occurs not in dummy_hcd thus I'm not sure how dummy_hcd can find out that it failed in order to reconnect the device to hs_hcd. And I'm not sure that dummy_hcd should care whether the enumeration succeeds or fails. It seems to me that this should be handled by upper levels. Shouldn't it? But we're discussing a more general issue; do you remember what the usb30 spec sais about this? I mean when connecting a HS device to a SS port (over SS cable), should it still enumerate as a HS device? It seems to me that the answer is no but I'm not sure...
> > > 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 :-) >
Hmmm.... I have v2.6.38 installed on my Linux-host at the moment and I just verified that when connecting a Gadget driver without SS descriptors over SS connection - the enumeration fails. Was this fixed in v2.6.39? It will take me some time to upgrade to v2.6.39 and verify but I have to do it any way so I'll give it a shot...
Best regards, Tanya Brokhman Consultant for Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
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