On Tuesday 27 October 2009 22:20:05 Greg KH wrote:
> On Tue, Oct 27, 2009 at 10:00:21PM +0100, Michael Buesch wrote:
> > Hi Greg,
> >
> > The following fields are byteswapped in lsusb on BigEndian machines:
> >
> > wTotalLength (Config descriptor)
> > wMaxPacketSize (EP descriptor)
>
> How so? Can you provide the output of 'lsusb -v' so I can see it?
Here's an example prototype device for which I know what the values must look like.
Other devices look similiar.
wTotalLength 12288 is 0x30 swapped.
wMaxPacketSize 0x4000 is 0x40 swapped.
0x30 and 0x40 would be the correct values. So it certainly is a byteorder issue.
This is lsusb version 0.73 (Debian Lenny stable). I didn't try a newer upstream version.
Bus 003 Device 035: ID 6666:1337 Prototype product Vendor ID
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 16
idVendor 0x6666 Prototype product Vendor ID
idProduct 0x1337
bcdDevice 0.01
iManufacturer 1 Michael Buesch
iProduct 2 PDIUSB test device
iSerial 3 1
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 12288
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 Configuration 1
bmAttributes 0xc0
Self Powered
MaxPower 50mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 1 Boot Interface Subclass
bInterfaceProtocol 2 Mouse
iInterface 5 Interface 1
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.11
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 65
Report Descriptors:
** UNAVAILABLE **
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x4000 1x 0 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x4000 1x 0 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x4000 1x 0 bytes
bInterval 1
Device Status: 0x0000
(Bus Powered)
--
Greetings, Michael.
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
