Re: Warning due to "ALSA: hda: intel: More comprehensive PM runtime setup for controller driver"

[Takashi Iwai <tiwai@suse.de>]

On Thu, 18 Nov 2021 21:33:34 +0100,
Heiner Kallweit wrote:
> 
> I get the following warning caused by 4f66a9ef37d3 ("ALSA: hda: intel: More
> comprehensive PM runtime setup for controller driver"):
> 
> snd_hda_intel 0000:00:1f.3: Unbalanced pm_runtime_enable!
> 
> Not sure how this patch was tested because the warning is obvious.
> The patch doesn't consider what the PCI sub-system does with regard to
> RPM. Have a look at pci_pm_init().
> 
> I'd understand to add the call to pm_runtime_dont_use_autosuspend(),
> but for all other added calls I see no justification.
> 
> If being unsure about when to use which RPM call best involve
> linux-pm@vger.kernel.org.

Thanks for the notice.  It's been through Intel CI and tests on a few
local machines, maybe we haven't checked carefully those errors but
only concentrated on the other issues, as it seems.

There were two problems: one was the runtime PM being kicked off even
during the PCI driver remove call, and another was the proper runtime
PM setup after re-binding.

For avoiding the former, only the pm_runtime_forbid() (and maybe
pm_runtime_dont_use_autosuspend(), too) would suffice?  Also, for PCI
device, no need for pm_runtime_set_supended() at remove, right?


thanks,

Takashi