From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko Schocher Date: Thu, 21 Aug 2014 07:25:13 +0200 Subject: [U-Boot] dfu: some wrong usb_qualifier_descriptor settings? Message-ID: <53F582B9.40705@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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 -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany