05ac:8507 iSight webcam on MacBook Pro does not work

[wvengen]

While in previous installations of Ubuntu the iSight webcam did often work (though I have had some problems in the past), it does not work anymore after a fresh install.
    $ sudo dmidecode -s system-product-name
    MacBookPro5,5
    $ lsusb | grep -i isight
    Bus 001 Device 004: ID 05ac:8507 Apple, Inc. Built-in iSight
    $ dmesg | tail | remove_not_really_interesting_lines
    [150678.498465] Linux video capture interface: v2.00
    [150678.536811] uvcvideo: Probing generic UVC device 4
    [150678.536825] uvcvideo: Found format YUV 4:2:2 (YUYV).
    [150678.536827] uvcvideo: - 160x120 (30.0 fps)
    (...)
    [150678.536834] uvcvideo: - 640x480 (30.0 fps)
    [150678.536837] uvcvideo: Found a Status endpoint (addr 81).
    [150678.536839] uvcvideo: Found UVC 1.00 device Built-in iSight (05ac:8507)
    (...)
    [150678.536902] uvcvideo: Scanning UVC chain: OT 2
    [150678.536904] uvcvideo: Found reference to unknown entity 170.
    [150678.536905] uvcvideo: No valid video chain found.
    [150678.537371] usbcore: registered new interface driver uvcvideo
    [150678.537374] USB Video Class driver (1.1.1)

I tried using isight-firmware-tools, but the usb id shows that the firmware does not need to be loaded (and ift-load says so).

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: linux-image-3.8.0-30-lowlatency 3.8.0-30.22
ProcVersionSignature: Ubuntu 3.8.0-30.22-lowlatency 3.8.13.6
Uname: Linux 3.8.0-30-lowlatency x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.9.2-0ubuntu8.3
Architecture: amd64
Date: Mon Sep 30 18:06:27 2013
EcryptfsInUse: Yes
InstallationDate: Installed on 2013-09-03 (27 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
MarkForUpload: True
SourcePackage: linux-lowlatency
UpgradeStatus: No upgrade log present (probably fresh install)

[penalvch (penalvch)]

wvengen, could you please confirm this issue exists with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ . If the issue remains, could you please run the following command in the development release from a Terminal (Applications->Accessories->Terminal), as it will automatically gather and attach updated debug information to this report:

apport-collect -p linux <replace-with-bug-number>

Also, could you please test the latest upstream kernel available following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Please do not test the daily kernel folder, but the one all the way at the bottom. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.12-rc3

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]