Volume turns up upon connecting USB webcam

[Tom Slominski]

Hi. I'm using Ubuntu 14.04 (fully updated) on my System76 Gazelle Professional (version 7) laptop. I recently noticed that after connecting a USB webcam (Bus 003 Device 008: ID 046d:081b Logitech, Inc. Webcam C310) while outputting sound via the sound output jack (VIA VT1802, Green Headphone Out, Front) at the side ramps up the volume of the output. For example:

1) Connect speakers via the output 3.5mm jack and play some music on either a distinctly low or high volume.
2) Connect a USB webcam.
3) Sound volume is set to 56 (as per alsamixer).

This happens both when the volume is lower and higher than 56. After disconnecting the webcam, the volume doesn't return to normal. You can imagine this is particularly annoying when using headphones!

If you want any other information, please do ask.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: alsa-base 1.0.25+dfsg-0ubuntu4
ProcVersionSignature: Ubuntu 3.11.0-19.33-generic 3.11.10.5
Uname: Linux 3.11.0-19-generic x86_64
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: tom 2934 F.... pulseaudio
 /dev/snd/controlC0: tom 2934 F.... pulseaudio
 /dev/snd/pcmC0D0p: tom 2934 F...m pulseaudio
Date: Thu Apr 10 17:08:25 2014
EcryptfsInUse: Yes
InstallationDate: Installed on 2013-06-09 (304 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
Symptom_Card: Built-in Audio - HDA Intel PCH
Symptom_Jack: Green Headphone Out, Front
Symptom_Type: Volume slider, or mixer problems
Title: [Gazelle Professional, VIA VT1802, Green Headphone Out, Front] volume slider problem
UpgradeStatus: Upgraded to saucy on 2013-10-17 (174 days ago)
dmi.bios.date: 05/16/2012
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 4.6.5
dmi.board.asset.tag: Tag 12345
dmi.board.name: Gazelle Professional
dmi.board.vendor: System76, Inc.
dmi.board.version: gazp7
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: No Enclosure
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr4.6.5:bd05/16/2012:svnSystem76,Inc.:pnGazelleProfessional:pvrgazp7:rvnSystem76,Inc.:rnGazelleProfessional:rvrgazp7:cvnNoEnclosure:ct9:cvrN/A:
dmi.product.name: Gazelle Professional
dmi.product.version: gazp7
dmi.sys.vendor: System76, Inc.

[Raymond (superquad-vortex2)]

[30922.455027] WARNING: CPU: 6 PID: 16839 at /build/buildd/linux-3.11.0/drivers/net/wireless/iwlwifi/dvm/../iwl-trans.h:694 iwlagn_mac_flush+0x18b/0x1a0 [iwldvm]()
[30922.455029] iwl_trans_wait_tx_queue_empty bad state = 0
[30922.455030] Modules linked in: usb_storage snd_usb_audio snd_usbmidi_lib hid_generic hidp hid ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle xt_tcpudp bridge stp llc pci_stub vboxpci(OF) vboxnetadp(OF) vboxnetflt(OF) ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables vboxdrv(OF) joydev parport_pc ppdev bnep rfcomm binfmt_misc dm_crypt x86_pkg_temp_thermal snd_hda_codec_hdmi intel_powerclamp coretemp kvm_intel kvm snd_hda_codec_via crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw uvcvideo gf128mul glue_helper videobuf2_vmalloc ablk_helper snd_hda_intel videobuf2_memops cryptd arc4 videobuf2_core snd_hda_codec videodev snd_hwdep snd_pcm btusb iwldvm bluetooth snd_page_alloc snd_seq_midi snd_seq_midi_event mac80211 snd_rawmidi iwlwifi microcode psmouse rtsx_pci_ms cfg80211 serio_raw snd_seq memstick lpc_ich snd_seq_device snd_timer snd mei_me soundcore mei mac_hid lp parport btrfs xor zlib_deflate raid6_pq libcrc32c rtsx_pci_sdmmc ahci i915 libahci r8169 rtsx_pci mii wmi video i2c_algo_bit drm_kms_helper drm
[30922.455090] CPU: 6 PID: 16839 Comm: kworker/u16:0 Tainted: GF O 3.11.0-19-generic #33-Ubuntu
[30922.455092] Hardware name: System76, Inc. Gazelle Professional/Gazelle Professional, BIOS 4.6.5 05/16/2012
[30922.455122] Workqueue: phy0 ieee80211_sta_monitor_work [mac80211]
[30922.455124] 0000000000000009 ffff8800c2563ca8 ffffffff816e87f1 ffff8800c2563cf0
[30922.455127] ffff8800c2563ce0 ffffffff81061e2d ffff880211af17a0 ffff880211af17e8
[30922.455130] ffff8802112d4000 ffff880211af17b0 0000000000000200 ffff8800c2563d40
[30922.455133] Call Trace:
[30922.455143] [<ffffffff816e87f1>] dump_stack+0x45/0x56
[30922.455148] [<ffffffff81061e2d>] warn_slowpath_common+0x7d/0xa0
[30922.455151] [<ffffffff81061e9c>] warn_slowpath_fmt+0x4c/0x50
[30922.455160] [<ffffffffa05997ab>] iwlagn_mac_flush+0x18b/0x1a0 [iwldvm]
[30922.455176] [<ffffffffa043e7bd>] ieee80211_flush_queues+0xbd/0x140 [mac80211]
[30922.455188] [<ffffffffa0453d24>] ieee80211_mgd_probe_ap_send+0xa4/0x140 [mac80211]
[30922.455192] [<ffffffff810115c6>] ? __switch_to+0x126/0x4b0
[30922.455203] [<ffffffffa04538ce>] ? ieee80211_recalc_ps.part.21+0xce/0x200 [mac80211]
[30922.455207] [<ffffffff810915b0>] ? finish_task_switch+0x50/0xf0
[30922.455218] [<ffffffffa0453ebd>] ieee80211_mgd_probe_ap.part.22+0xfd/0x170 [mac80211]
[30922.455227] [<ffffffffa0453f5a>] ieee80211_sta_monitor_work+0x2a/0x30 [mac80211]
[30922.455231] [<ffffffff8107d0ec>] process_one_work+0x17c/0x430
[30922.455235] [<ffffffff8107dd3c>] worker_thread+0x11c/0x3c0
[30922.455237] [<ffffffff8107dc20>] ? manage_workers.isra.25+0x2a0/0x2a0
[30922.455241] [<ffffffff810848d0>] kthread+0xc0/0xd0
[30922.455244] [<ffffffff81084810>] ? kthread_create_on_node+0x120/0x120
[30922.455248] [<ffffffff816f85ec>] ret_from_fork+0x7c/0xb0
[30922.45525...

[Raymond (superquad-vortex2)]

Apr 10 17:04:38 gazelle pulseaudio[2934]: [alsa-source-USB Audio] alsa-util.c: Got POLLNVAL from ALSA
Apr 10 17:04:38 gazelle pulseaudio[2934]: [alsa-source-USB Audio] alsa-util.c: Could not recover from POLLERR|POLLNVAL|POLLHUP with snd_pcm_prepare(): No such device

[Marcus Tomlinson (marcustomlinson)]

This release of Ubuntu is no longer receiving maintenance updates. If this is still an issue on a maintained version of Ubuntu please let us know.

[Launchpad Janitor (janitor)]

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