diff options
| author | Hans de Goede <hdegoede@redhat.com> | 2013-08-03 16:37:49 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-12 12:24:27 -0700 |
| commit | 21a9631586a07198e22d278fb8695bdd74d9b5c5 (patch) | |
| tree | 0f78064a58bb5e9b2a40581ca40e2826d2bbdaf1 /Documentation/usb | |
| parent | b4f17a488ae2e09bfcf95c0e0b4219c246f1116a (diff) | |
proc_usb_info.txt: Correct documentation about endianness of config descriptors
The config descriptors as read from /proc/bus/usb/BBB/DDD are in *bus* endian
format. Correct proc_usb_info.txt to correctly reflect that.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/usb')
| -rw-r--r-- | Documentation/usb/proc_usb_info.txt | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/Documentation/usb/proc_usb_info.txt b/Documentation/usb/proc_usb_info.txt index c9c3f0f5ad7..98be9198267 100644 --- a/Documentation/usb/proc_usb_info.txt +++ b/Documentation/usb/proc_usb_info.txt @@ -54,9 +54,12 @@ it and 002/048 sometime later. These files can be read as binary data. The binary data consists of first the device descriptor, then the descriptors for each -configuration of the device. Multi-byte fields in the device and -configuration descriptors, but not other descriptors, are converted -to host endianness by the kernel. This information is also shown +configuration of the device. Multi-byte fields in the device descriptor +are converted to host endianness by the kernel. The configuration +descriptors are in bus endian format! The configuration descriptor +are wTotalLength bytes apart. If a device returns less configuration +descriptor data than indicated by wTotalLength there will be a hole in +the file for the missing bytes. This information is also shown in text form by the /proc/bus/usb/devices file, described later. These files may also be used to write user-level drivers for the USB |