[U-Boot] dfu: some wrong usb_qualifier_descriptor settings?

[Heiko Schocher]

Hello Lukasz,

Am 22.08.2014 14:11, schrieb Lukasz Majewski:
> Hi Heiko,
>
>> Hello Lukasz,
>>
>> In the dfu spez [1] chapter 4.2.1 the following fields are specified:
>>
>> bDeviceClass = 00h (Description: „see interface“), currently set in
>> U-Boot to 2.
>>
>> bDeviceSubClass = 00h (Description: „see interface“), currently set in
>> U-Boot to 2.
>>
>> bcdUSB = xxxxh (Description: USB specification release number in
>> binary coded decimal ->  0110h) Currently set to 0x200
>>
>> If I look in ./drivers/usb/gadget/f_dfu.c:
>>
>> static const struct usb_qualifier_descriptor dev_qualifier = {
>>           .bLength =              sizeof dev_qualifier,
>>           .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
>>           .bcdUSB =               __constant_cpu_to_le16(0x0200),
>>           .bDeviceClass =         USB_CLASS_VENDOR_SPEC,
>>           .bNumConfigurations =   1,
>> };
>>
>> bDeviceClass = USB_CLASS_VENDOR_SPEC = 0xff ?
>>
>>     Hmm... why states the doc this should be set to 0 =
>> USB_CLASS_PER_INTERFACE? 2 is USB_CLASS_COMM ... which seems more
>> appropriate ...
>
> The bDeviceClass seems to be set to wrong value. I think that it should
> have values as they are specified by the standard.
>
>>
>> bDeviceSubClass is not defined ...
>> bcdUSB = 0x0200 which should be 0x0110 ... oh, as [1] is the dfu 1.1
>> specification it should be 0x0110 but the spec [1] says 0100 ... is
>> the spec here buggy? is there a dfu 2.0 specification availiable?
>
> The 2.0 value is a reminiscent of the original DFU code (once prepared
> for Linux) and was wrongly set to indicate USB 2.0.
>
> I think that we should have 0x0110, which indicates supported DFU
> version 1.1.
>
>>
>> Has this differences to the spec some reason? Or can we change them
>> to the values specified in the spec?
>
> I think that values which you have pointed out are wrong and should be
> changed to the one from spec.

Thanks! Changed. I send a patch soon.

bye,
Heiko
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany