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dfu: some wrong usb_qualifier_descriptor settings?

U-Boot Heiko Schocher 2 participants 3 messages Aug 21, 2014 – Aug 25, 2014

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Heiko Schocher

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#0 lore raw

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 ...

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?

Has this differences to the spec some reason? Or can we change them to the values specified in the spec?

Thanks!

bye,
Heiko

[1]: http://www.usb.org/developers/devclass_docs/DFU_1.1.pdf

Signature · 2 lines
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
#1 lore raw

Hi Heiko,

Quoted 21 lines

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,
Quoted 7 lines

};

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.

Quoted 5 lines

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.

Quoted 3 lines

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.

Quoted 7 lines

Thanks!

bye,
Heiko

[1]: http://www.usb.org/developers/devclass_docs/DFU_1.1.pdf

Signature · 5 lines
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
author
#2 lore raw

Hello Lukasz,

Am 22.08.2014 14:11, schrieb Lukasz Majewski:

Quoted 47 lines

Hi Heiko,

Quoted 21 lines

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,
Quoted 7 lines

};

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.

Quoted 5 lines

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.

Quoted 1 line
Quoted 5 lines
Quoted 2 lines

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

Signature · 2 lines
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany