On Wed, 16 Dec 2020 16:50:20 +0100, Kai-Heng Feng wrote:
On Wed, Dec 16, 2020 at 11:41 PM Takashi Iwai tiwai@suse.de wrote:
On Wed, 16 Dec 2020 13:47:24 +0100, Kai-Heng Feng wrote:
Similar to commit 9479e75fca37 ("ALSA: hda: Keep the controller initialization even if no codecs found"), when codec probe fails, it doesn't enable runtime suspend, and can prevent graphics card from getting powered down: [ 4.280991] snd_hda_intel 0000:01:00.1: no codecs initialized
$ cat /sys/bus/pci/devices/0000:01:00.1/power/runtime_status active
So mark there's no codec and continue probing to let runtime PM to work.
BugLink: https://bugs.launchpad.net/bugs/1907212 Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com
Hm, but if the probe fails, doesn't it mean something really wrong? IOW, how does this situation happen?
The HDA controller is forcely created by quirk_nvidia_hda(). So probably there's really not an HDA controller.
I still don't understand how non-zero codec_mask is passed. The non-zero codec_mask means that BIOS or whatever believes that HD-audio codecs are present and let HD-audio controller reporting the presence. What error did you get at probing?
The usual no-codec state is for the devices that have a bogus HD-audio bus remaining while codecs aren't hooked or disabled by BIOS. For that, it makes to leave the controller driver and let it idle. But if you get really an error, it's something to fix there, not to just ignore in general.
The best approach I can think of is to make current two steps probe into one. So when probe fails, the driver won't bind to the device. What's the reason behind the two steps approach?
It's a sort of must, as the module loading is involved with binding with the codecs, as well as (optionally) request_firmware() invocation.
Takashi