Running sys-kernel/gentoo-sources-4.1.12. When the uvcvideo is loaded, dmesg shows the message: "uvcvideo: No valid video chain found." And no "/dev/videoX" is being created. Searching the web, I found the same problem happening in other distros. This bug report under Ubuntu's bug tracker includes a patch for this module which helped me to get the module working under my gentoo running on a ThinkPad E555. * Bug report in ubuntu https://bugs.launchpad.net/ubuntu/+source/linux-lts-utopic/+bug/1433906 * URL for patch https://bugs.launchpad.net/ubuntu/+source/linux-lts-utopic/+bug/1433906/+attachment/4536648/+files/uvc.patch After applying this patch, the module is running and no the "/dev/video0" is being created, and now video applications can have acceess to it. Here's my system info: * dmesg "before patch" [ 25.489612] uvcvideo: Found UVC 1.00 device Integrated Camera (5986:055a) [ 25.489694] uvcvideo: No valid video chain found. [ 25.489775] usbcore: registered new interface driver uvcvideo [ 25.489778] USB Video Class driver (1.1.1) * dmesg "after patch" [ 5022.786490] uvcvideo: Found UVC 1.00 device Integrated Camera (5986:055a) [ 5022.790920] input: Integrated Camera as /devices/pci0000:00/0000:00:13.2/usb2/1/2-1:1.0/input/input14 [ 5022.791137] usbcore: registered new interface driver uvcvideo [ 5022.791142] USB Video Class driver (1.1.1) * lsusb output Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 002: ID 5986:055a Acer, Inc Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 002: ID 0bda:b728 Realtek Semiconductor Corp. * eselect kernel list Available kernel symlink targets: [1] linux-4.1.12-gentoo * * equery l sys-kernel/gentoo-sources [IP-] [ ] sys-kernel/gentoo-sources-4.1.12:4.1.12 * emerge --info Portage 2.2.24 (python 3.4.3-final-0, default/linux/amd64/13.0/desktop, gcc-4.9.3, glibc-2.21-r1, 4.1.12-gentoo x86_64) ================================================================= System uname: Linux-4.1.12-gentoo-x86_64-AMD_A10-7300_Radeon_R6,_10_Compute_Cores_4C+6G-with-gentoo-2.2 KiB Mem: 3346824 total, 181948 free KiB Swap: 8388604 total, 8382708 free Timestamp of repository gentoo: Thu, 14 Jan 2016 04:00:01 +0000 sh bash 4.3_p39 ld GNU ld (Gentoo 2.25.1 p1.1) 2.25.1 app-shells/bash: 4.3_p39::gentoo dev-lang/perl: 5.20.2::gentoo dev-lang/python: 2.7.10-r1::gentoo, 3.4.3::gentoo dev-util/cmake: 3.3.1-r1::gentoo dev-util/pkgconfig: 0.28-r2::gentoo sys-apps/baselayout: 2.2::gentoo sys-apps/openrc: 0.18.4::gentoo sys-apps/sandbox: 2.6-r1::gentoo sys-devel/autoconf: 2.13::gentoo, 2.69::gentoo sys-devel/automake: 1.11.6-r1::gentoo, 1.13.4::gentoo, 1.14.1::gentoo, 1.15::gentoo sys-devel/binutils: 2.25.1-r1::gentoo sys-devel/gcc: 4.9.3::gentoo sys-devel/gcc-config: 1.7.3::gentoo sys-devel/libtool: 2.4.6::gentoo sys-devel/make: 4.1-r1::gentoo sys-kernel/linux-headers: 3.18::gentoo (virtual/os-headers) sys-libs/glibc: 2.21-r1::gentoo Repositories: gentoo location: /usr/portage sync-type: rsync sync-uri: rsync://rsync.gentoo.org/gentoo-portage priority: -1000 ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="* -@EULA" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O2 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c" CXXFLAGS="-march=native -O2 -pipe" DISTDIR="/usr/portage/distfiles" FCFLAGS="-O2 -pipe" FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-O2 -pipe" GENTOO_MIRRORS="http://distfiles.gentoo.org" LANG="en_US.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" MAKEOPTS="-j5" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" USE="X a52 aac acl acpi alsa amd64 berkdb bindist bluetooth branding bzip2 cairo cdda cdr cli consolekit corefonts cracklib crypt cups cxx dbus dri dts dvd dvdr emacs emboss encode exif fam firefox flac fortran gdbm gif glamor gpm gtk iconv ipv6 jpeg lcms ldap libnotify mad mmx mmxext mng modules mp3 mp4 mpeg multilib ncurses networkmanager nls nptl ogg opengl openmp pam pango pcre pdf png policykit ppds readline sdl seccomp session spell sse sse2 ssl startup-notification svg tcpd thinkpad tiff truetype udev udisks unicode upower usb vorbis wxwidgets x264 xattr xcb xft xml xv xvid zlib" ABI_X86="64" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="mmx mmxext sse sse2" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="evdev synaptics" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-5" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7 python3_4" RUBY_TARGETS="ruby20 ruby21" USERLAND="GNU" VIDEO_CARDS="radeon radeonsi amdgpu" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CC, CPPFLAGS, CTARGET, CXX, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON Thanks
Sorry, there was a typo in my description: Instead of writing [After applying this patch, the module is running and no the "/dev/video0" is being created ...] What I really meant to say is that after applying the patch, the "/dev/video0" is created and my webcam is working OK.
from the link referred this bug is fixed upstream
please open a new bug if is still a problem
