Some Problematic Laptops On Linux Will Soon Stop Making Loud Noises When You Reboot
Shortly after writing about the Sound Blaster Recon3D finally getting Linux support yesterday, a Phoronix reader pointed out another frustrating Linux sound problem with a resolution on its way to the mainline Linux kernel.
The problem is that for some laptops like recent LG Gram and HP Spectre hardware, when rebooting the system there will be "extremely loud noises upon reboot." This isn't the first time we have heard of some faulty hardware making loud popping sounds or other disturbances under Linux in certain scenarios.
In the case of the recent HP Spectre laptops and others making these loud noises upon reboot, its the CX8200 audio codec they've deemed to be faulty. To workaround this, the kernel is forcing the codec into the D3 power-savings state ahead of reboots to eliminate the noises.
The Linux kernel has previously worked around similar issues for other Conexant chips including the CX20722 and CX20724.
Linux sound maintainer Takashi Iwai of SUSE has queued the ALSA: hda - Turn CX8200 into D3 as well upon reboot patch into his next pull request for Linus Torvalds. This patch is also queued for going into currently supported stable kernel branches too, so it should only be a short period of time before the problematic laptops will stop making disturbing noises on reboot.