From: Lukasz Majewski Date: Fri, 22 Aug 2014 14:11:09 +0200 Subject: [U-Boot] dfu: some wrong usb_qualifier_descriptor settings? In-Reply-To: <53F582B9.40705@denx.de> References: <53F582B9.40705@denx.de> Message-ID: <20140822141109.14f99144@amdc2363> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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! > > bye, > Heiko > > [1]: http://www.usb.org/developers/devclass_docs/DFU_1.1.pdf -- Best regards, Lukasz Majewski Samsung R&D Institute Poland (SRPOL) | Linux Platform Group