[U-Boot] [PATCH] dfu, usb: set usb descriptor to values defined in dfu spec 1.1

Fri Sep 5 10:11:23 CEST 2014

Hello Lukasz,

Am 05.09.2014 09:53, schrieb Lukasz Majewski:
> Hi Heiko,
>
>> Hello Marek,
>>
>> Am 05.09.2014 00:42, schrieb Marek Vasut:
>>> On Thursday, September 04, 2014 at 12:21:40 PM, Heiko Schocher
>>> wrote:
>>>
>>> Hi Heiko,
>>>
>>> I'll just rant a bit, but please wait until Lukasz does a proper
>>> runthrough.
>>>
>>>> set bDeviceClass, bDeviceSubClass and bcdUSB to the values
>>>> defined in dfu spec 1.1 chapter 4.2.1 found here:
>>>>
>>>> http://www.usb.org/developers/devclass_docs/DFU_1.1.pdf
>>>
>>> This URL gives me a website with:
>>> "
>>> Resource not found.
>>> Please check the URL and try again.
>>> "
>>
>> :-( Maybe it is deleted currently there?
>> Hmm.. there is a search field if you open the above URL ... and if
>> you type DFU and press search, you get:
>>
>> DFU
>> File Format: PDF/Adobe Acrobat
>> Aug 5, 2004 ... USB Device Firmware Upgrade Specification, Revision
>> 1.1. 2. Intellectual Property Disclaimer. THIS SPECIFICATION IS
>> PROVIDED “AS IS” ... www.usb.org/developers/devclass_docs/DFU_1.1.pdf
>>
>> This is exactly the above link ...
>>
>> This link is also referenced from openmoko:
>>
>> http://wiki.openmoko.org/wiki/USB_DFU_-_The_USB_Device_Firmware_Upgrade_standard
>
> I can confirm that the original link is dead. Maybe we can add above
> information to the commit message?

Hmm.. better would be to add a correct new link... do you have
an idea, where we can find this document now?

>>>> Signed-off-by: Heiko Schocher<hs at denx.de>
>>>> Cc: Lukasz Majewski<l.majewski at samsung.com>
>>>> Cc: Marek Vasut<marex at denx.de>
>>>> Cc: Roger Meier<r.meier at siemens.com>
>>>>
>>>> ---
>>>>
>>>> before this patch, "dfu-util -l" showed:
>>>>
>>>> Bus 002 Device 114: ID 0908:02c5 Siemens AG
>>>> Device Descriptor:
>>>>     bLength                18
>>>>     bDescriptorType         1
>>>>     bcdUSB               2.00
>>>>     bDeviceClass            2 Communications
>>>>     bDeviceSubClass         2 Abstract (modem)
>>>>     bDeviceProtocol         0 None
>>>>     bMaxPacketSize0        64
>>>>     idVendor           0x0908 Siemens AG
>>>>     idProduct          0x02c5
>>>>     bcdDevice            0.00
>>>>     iManufacturer           1 Siemens AG
>>>>
>>>> with this patch:
>>>>
>>>> Bus 002 Device 089: ID 0908:02c5 Siemens AG
>>>> Device Descriptor:
>>>>     bLength                18
>>>>     bDescriptorType         1
>>>>     bcdUSB               1.10
>>>>     bDeviceClass            0 (Defined at Interface level)
>>>>     bDeviceSubClass         0
>>>>     bDeviceProtocol         0
>>>>     bMaxPacketSize0        64
>>>>     idVendor           0x0908 Siemens AG
>>>>     idProduct          0x02c5
>>>>     bcdDevice            0.00
>>>>     iManufacturer           1 Siemens AG
>>>>     iProduct                2 USB download gadget
>>>>
>>>> which fits for "bcdUSB", "bDeviceClass" and "bDeviceSubClass" with
>>>> the DFU spezifikation.
>>>
>>> This patch doesn't seem fully right, let me explain below please.
>>>
>>>> ---
>>>>    drivers/usb/gadget/f_dfu.c | 5 +++--
>>>>    drivers/usb/gadget/g_dnl.c | 6 +++---
>>>>    2 files changed, 6 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/usb/gadget/f_dfu.c
>>>> b/drivers/usb/gadget/f_dfu.c index 9128add..9429e50 100644
>>>> --- a/drivers/usb/gadget/f_dfu.c
>>>> +++ b/drivers/usb/gadget/f_dfu.c
>>>> @@ -83,8 +83,9 @@ static struct usb_descriptor_header
>>>> *dfu_runtime_descs[] = { 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,
>>>> +	.bcdUSB =		__constant_cpu_to_le16(0x0110),
>>>
>>> See [1] and look for first and second instance of 'bcdUsb' there
>>> please. Quote of the second one:
>>>
>>> '
>>> The bcdUSB field reports the highest version of USB the device
>>> supports. The value is in binary coded decimal with a format of
>>> 0xJJMN where JJ is the major version number, M is the minor version
>>> number and N is the sub minor version number. e.g. USB 2.0 is
>>> reported as 0x0200, USB 1.1 as 0x0110 and USB 1.0 as 0x0100.
>>> '
>>>
>>> So this should be configured dynamically based on what the highest
>>> mode the controller supports is, no?
>>
>> Good question ... the DFU 1.1 spezification says in chapter
>> 4.2.1 DFU Mode Device Descriptor:
>>
>> bcdUSB = 0100  USB specification release number in binary coded
>> decimal. (which seems wrong, as the spez is version 1.1, see [2])
>> bDeviceClass = 0
>> bDeviceSubClass = 0
>>
>> ... ?
>>
>> I discussed this change with Lukasz, see:
>>
>> [2] http://lists.denx.de/pipermail/u-boot/2014-August/186918.html
>>
>
> I'm more than happy to announce that you both may be right :-).

;-)

> In the DFU 1.1 spec the point 4.2.1 describes the DFU MODE DEVICE
> DESCRIPTOR.
>
> According to information from point 4.- "Enumeration Phase":
>
> "It is very important to note that the device exposes two distinct and
> independent descriptor sets, one each at the appropriate time:
> - Run-time descriptor (the one from [1] pointed out by Marek)
> - DFU mode descriptor (the one from 4.2.1. - fixed by Heiko)
>
> It seems to me that the first descriptor is defined at g_dnl.c and the
> second, which I guess should be changed, at f_dfu.c

Ah, I fixed both ...

> However, to be 100% sure I need to examine this with USB analizer. I'm
> going to setup it today or on Monday.

Oh, that would be great, thanks!

bye,
Heiko
>
>>>
>>>> +	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
>>>
>>> This might be OK.
>>>
>>>> +	.bDeviceSubClass =	0x00,
>>>
>>> But this is not, the device definitelly isn't CDC-serial.
>>>
>>> [...]
>>>
>>> [1] http://www.beyondlogic.org/usbnutshell/usb5.shtml
>>
>> bye,
>> Heiko
>
>

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