DC offset when recording audio with Realtek ALC268
Hi. I am running debian sid on a Compal IFL90. It has a Realtek ALC268 sound card. I configured ALSA with options snd-hda-intel model=toshiba in /etc/modprobe.d/alsa-base. The sound output works fine, but when recording, there is a significant DC offset from both the built-in mics and the mic jack even when nothing is plugged in. The offset increases when the capture volume and mic boost is increased, so I cannot record with very much volume before the sound is clipped. This makes the built-in mics useless, because the capture volume must be turned up very high. Is this a hardware problem in my sound card, or is it an issue with the software, and can I fix it?