Am Donnerstag, 21. Mai 2015, 06:28:24 schrieb Takashi Iwai:
At Wed, 20 May 2015 16:31:55 +0200,
Martin Steigerwald wrote:
Hello!
On ThinkPad T520 (Intel Sandybridge) with 4.14-rc4 + two BTRFS patches and one Intel P-State debug patch I have no sound output on internal Intel HD audio codec.
According to ThinkPad T520 LED with striked-through speaker the loud speaker is in disabled state. Also KDE´s Phonon says a soundcard is missing. In alsa-mixer I see nothing as MM for muted. If I press the key next to the LED I get a notification on the desktop that loud speaker has been enabled / disabled, but the LED still is on for it being disabled.
One clarification: Phonon still seems to see a sound card… but it reports a change to the list of soundcards.
And another observation: The speaker disable LED is switched on KDE/Plasma 4.14.2 session startup, I just rebooted to 4.1-rc4 after I gathered debug output of 4.0.1, and there on boot the speaker disable LED was off during boot.
So there seems Phonon is confused about some difference in ALSA between these two kernel versions and probably doesn´t fully find the sound card or mutes it, but on the other hand I can´t see it in alsa-mixer as muted.
And alsa-mixer still finds the internal sound.
Also this does not happen for external USB JBL Pebbles speakers (excellent ones!) at home, sound just works with 4.1-rc4 with these.
I am now on 4.1-rc4 again so could try to dig out more what KDE Phonon sees as a difference. In trainings breaks. Now need to continue with the course I hold.
Phonon runs without PulseAudio here, cause PulseAudio creates additional issues with sound. Okay, this is the message I get:
KDE hat festgestellt, dass eines oder mehrere interne Geräte entfernt wurden. Soll KDE die Informationen zu diesen Geräten dauerhaft löschen? Dies ist die Liste der Geräte, die entfernt werden können: Aufnahme: HDA Intel PCH (CX20590 Analog) Wiedergabe: HDA Intel PCH (CX20590 Analog)
Which means: KDE has found that one or more internal devices were removed.
So it seems KDE really does not find the sound card anymore, while alsa-mixer finds it, yet, also aplay does not produce any sound.
But then I still have a "HDA Intel PCH (CX20590 Analog)" in systemsettings for Phonon. There is one greyed out and another one which is not greyed out, but does not produce any sound on clicking the test button either.
I do not hear anything in Amarok or with aplay. alsa-mixer sound volumes are 100 for master and PCM. I also tried with disabling "Auto-Mute Mod", but still no sound.
When I reboot and in BIOS or GRUB press the key then the LED toggles state.
When I reboot into Linux 4.0.1 sound is working fine and loud speaker disabled LED is toggled off, so I bet this is a regression 4.1-rc4 compared to 4.0.1.
Please run alsa-info.sh at both working and non-working cases (with old and new kernels), and attach the outputs. Run the script with --no-upload option.
I sent a separate mail with these already.
Also, such a problem is rather the device permissions problem. Check the device permissions of /dev/snd/* files (also check getfacl /dev/snd/*, too).