I'm had the similar problem with my Toshiba L750D - with the same sound card on Kubuntu 14.04. Then I switched to Fedora Core 20 - and it worked OK with the open source radeon driver. As soon as I installed proprietary graphics card AMD driver, the problem reoccurred.
I'm had the similar problem with my Toshiba L750D - with the same sound card on Kubuntu 14.04. Then I switched to Fedora Core 20 - and it worked OK with the open source radeon driver. As soon as I installed proprietary graphics card AMD driver, the problem reoccurred.