Ubuntu
libusb package

sync libusb usb_set_configuration() + sysfs .../bConfigurationValue

Bug #347405 reported by Paul Sladen
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
libusb (Ubuntu)
New
Undecided
Unassigned
linux (Ubuntu)
Incomplete
Undecided
Unassigned

Bug Description

A USB device can offering a number of possible Configurations, with the host/operating system selecting the most suitable configuration for its needs. An example could be a media device offering either proprietary, or Mass Storage configurations.

Changing the selected configuration can be done by either:

  echo 3 > /sys/devices/pci0000:00/0000:00:1d.7/usb7/7-3/bConfigurationValue

or, using libusb:

  usb_set_configuration(iphone->device, 3);

Currently using one of these methods means that the kernel sysfs state gets out-of-sync; meaning that udev events are incorrect and the available '/dev/usbdev7.3_ep??' endpoint symlinks are incorrect as no udev events are issued.

Ideally 'libusb' should use sysfs on Linux to make the configuration change, or the kernel should make note of the raw USB commands that it passes through and update its state.

Revision history for this message
Paul Sladen (sladen) wrote :

<Keybuk> the raw devices nodes are *beneath* the host
<Keybuk> they're there so you can bypass the host entirely
<Keybuk> that's kinda the difficult point
<sladen> yeah it's like raw ethernet access and complaining that you're sending ARP updates that don't match the kernel ARP table

Revision history for this message
Jeremy Foshee (jeremyfoshee) wrote :

Hi Paul,

This bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? Can you try with the latest development release of Ubuntu? ISO CD images are available from http://cdimage.ubuntu.com/releases/lucid.

If it remains an issue, could you run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux 347405

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

tags: added: needs-kernel-logs
tags: added: needs-upstream-testing
tags: added: kj-triage
Changed in linux (Ubuntu):
status: New → Incomplete
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