RE: [PATCH v12 7/8] usb: Adding SuperSpeed support to dummy_hcd

From: Tanya Brokhman
Date: Tue May 24 2011 - 06:41:32 EST


Hi Felipe

> > Yes :) The driver->speed is updated in usb_composite_probe() if
> > CONFIG_USB_GADGET_SUPERSPEED is defined.
> >
> > So, are we ok with this solution? The module parameter I mean?
> > Are you going to try the v13 in your branch? Please let me know how
> it
> > goes and of course if you have any comments.
>
> I think it still gives the possibility for failure. I would rather not
> take that until all gadget drivers are fixed. We can help you doing
> that and we only change driver->speed after all gadget drivers have
> their "sensible defaults" SuperSpeed descriptors.

By "until all gadget drivers are fixed" you mean until all gadget drivers
provide SS descriptors? This will take for ever...
I wasn't about to modify all gadget drivers and to add SS descriptors for
them. I can add default values (as generate_ss_descriptors() did if you
remember) but I don't think this is the right approach because as you said -
different gadget drivers might have different SS descriptors and I don't
feel confident enough to set these values. Nor do I have the ability to test
each of the gadget drivers the way I would like to after this change.
The only gadget driver I felt confident adding SS descriptors for is UASP,
which I tested properly.

Actually if the CONFIG_USB_GADGET_SUPERSPEED is turned off, which is the
default of it, the speed won't be updated and all these series won't be
functional so I don't see any possibilities for failure in such
configuration. Or am I missing something?


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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