Ubuntu
alsa-driver package

  1. Bug #879790
  2. Comment #28

Comment 28 for bug 879790

Revision history for this message
In , JasonPorter (jasonporter) wrote :

Several Launchpad bug reports in process report radeon KMS conflicts with Intel wifi and audio output, causing wireless to hang/drop until power cycle and audio to crackle during any high GPU load. Disabling KMS as a workaround returns normal system operation.

Relevant Launchpad reports:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/564376
https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/578342
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/571770
And one on Bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=15912

My own hardware is a Thinkpad T60 with Radeon X1400 and Intel wireless (iwl3945 driver) running vanilla Ubuntu 10.04. Users of Radeon X1250, X1300, and Xpress 200M chipsets have also reported the same behavior, on Lenovo, Dell and LG laptops. Using a mainline kernel does not change the behavior.

This may possibly be due to a difference in PCI configuration between KMS and UMS, they use different IRQs for "Pin A" as detailed in the Bugzilla report linked above.

Thanks for any assistance you can provide! And thanks for all your hard work!