On Tuesday 27 October 2009 23:38:29 Greg KH wrote:
> On Tue, Oct 27, 2009 at 11:28:16PM +0100, Michael Buesch wrote:
> > 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.
>
> This was fixed back in May of 2006 and should have showed up in the 0.73
> release. If you could, can you grab a newer version of usbutils, like
> the upstream version, to see if it is still an issue or not?
version 0.86 shows the same behavior.
The endianness check in lsusb.c does also work correctly.
The following patch will produce the correct result.
However, the patch obviously is incorrect.
I suspect that libusb (or the kernel) already swapped the values for us.
Look at those other 16bit values like idProduct, idVendor, bcdXXX...
Those are correctly displayed and usbutils does _not_ byteswap them.
So I guess either libusb (or the kernel) does.
--- usbutils-0.86.orig/lsusb.c
+++ usbutils-0.86/lsusb.c
@@ -41,7 +41,7 @@
#include <getopt.h>
-#if (__BYTE_ORDER == __LITTLE_ENDIAN)
+#if (__BYTE_ORDER == __LITTLE_ENDIAN) ||1
#define le16_to_cpu(x) (x)
#elif (__BYTE_ORDER == __BIG_ENDIAN)
#define le16_to_cpu(x) bswap_16(x)
Broken output from unpatched 0.86:
Bus 003 Device 036: ID 6666:1337
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.00
bDeviceClass 0
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 16
idVendor 0x6666
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
bInterfaceSubClass 1
bInterfaceProtocol 2
iInterface 5 Interface 1
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.11
bCountryCode 0 Unknown
bNumDescriptors 1
bDescriptorType 34 (null)
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.
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