# lspci|grep Audio 00:1b.0 Audio device: Intel Corporation NM10/ICH7 Family High Definition Audio Controller (rev 02) With kernel-3.14.9-200.fc20.i686 audio volume is OK, with kernel-3.15.3-200.fc20.i686 even when mixer volume is 100%, the sound is lower than 3.14.x kernel and mixer volume 50%.
dmesg|grep -i sound does not give any output on 3.14.9-200, but on 3.15.3-200: [ 20.572292] sound hdaudioC0D0: CX20549 (Venice): BIOS auto-probing. [ 20.572559] sound hdaudioC0D0: autoconfig: line_outs=1 (0x10/0x0/0x0/0x0/0x0) type:speaker [ 20.572563] sound hdaudioC0D0: speaker_outs=0 (0x0/0x0/0x0/0x0/0x0) [ 20.572567] sound hdaudioC0D0: hp_outs=1 (0x11/0x0/0x0/0x0/0x0) [ 20.572570] sound hdaudioC0D0: mono: mono_out=0x0 [ 20.572574] sound hdaudioC0D0: dig-out=0x13/0x0 [ 20.572577] sound hdaudioC0D0: inputs: [ 20.572581] sound hdaudioC0D0: Mic=0x14 [ 20.572584] sound hdaudioC0D0: Line=0x12 [ 20.572588] sound hdaudioC0D0: CD=0x15 [ 20.574077] sound hdaudioC0D0: Enable sync_write for stable communication [ 20.585615] input: HDA Intel Line as /devices/pci0000:00/0000:00:1b.0/sound/card0/input8 [ 20.585819] input: HDA Intel Headphone as /devices/pci0000:00/0000:00:1b.0/sound/card0/input9
lsmod|grep snd output on 3.14.9-200: snd_hda_codec_conexant 47818 1 snd_hda_codec_generic 57111 1 snd_hda_codec_conexant snd_hda_intel 42689 4 snd_hda_codec 111410 3 snd_hda_codec_conexant,snd_hda_codec_generic,snd_hda_intel snd_hwdep 13232 1 snd_hda_codec snd_seq 54679 0 snd_seq_device 13824 1 snd_seq snd_pcm 83092 3 snd_hda_codec,snd_hda_intel snd_timer 23750 2 snd_pcm,snd_seq snd 59345 16 snd_hwdep,snd_timer,snd_hda_codec_conexant,snd_pcm,snd_seq,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel,snd_seq_device soundcore 14123 1 snd On 3.15.3-200: snd_hda_codec_conexant 14314 1 snd_hda_codec_generic 61774 1 snd_hda_codec_conexant snd_hda_intel 29152 4 snd_hda_controller 29171 1 snd_hda_intel snd_hda_codec 112994 4 snd_hda_codec_conexant,snd_hda_codec_generic,snd_hda_intel,snd_hda_controller snd_hwdep 13232 1 snd_hda_codec snd_seq 55888 0 snd_seq_device 13824 1 snd_seq snd_pcm 91968 3 snd_hda_codec,snd_hda_intel,snd_hda_controller snd_timer 23814 2 snd_pcm,snd_seq snd 63701 17 snd_hwdep,snd_timer,snd_hda_codec_conexant,snd_pcm,snd_seq,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel,snd_seq_device soundcore 14123 2 snd,snd_hda_codec
I asked in the alsa list: It's because the volume was overloaded in 3.14 and earlier. It came through the mixer widget and it has the gain over 0dB. If you set 100% amp in the pin and sets more than 0dB in the mixer, it's basically more than 100%, overloading. That is, the new driver corrected the wrong volume setup. Takashi