> -----Original Message-----
> From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> Sent: Tuesday, May 12, 2020 8:46 PM
> To: Alex Deucher <alexdeucher@xxxxxxxxx>
> Cc: Takashi Iwai <tiwai@xxxxxxx>; Deucher, Alexander
> <Alexander.Deucher@xxxxxxx>; alsa-devel@xxxxxxxxxxxxxxxx; Mark Brown
> <broonie@xxxxxxxxxx>; Mukunda, Vijendar <Vijendar.Mukunda@xxxxxxx>
> Subject: Re: [PATCH v2 09/14] ASoC: amd: add Renoir ACP PCI driver PM ops
>
>
>
> On 5/12/20 8:46 AM, Alex Deucher wrote:
> > On Mon, May 11, 2020 at 6:37 PM Pierre-Louis Bossart
> > <pierre-louis.bossart@xxxxxxxxxxxxxxx> wrote:
> >>
> >>
> >>> @@ -233,6 +234,11 @@ static int snd_rn_acp_probe(struct pci_dev *pci,
> >>> ret = PTR_ERR(adata->pdev);
> >>> goto unregister_devs;
> >>> }
> >>> + pm_runtime_set_autosuspend_delay(&pci->dev,
> ACP_SUSPEND_DELAY_MS);
> >>> + pm_runtime_use_autosuspend(&pci->dev);
> >>> + pm_runtime_allow(&pci->dev);
> >>> + pm_runtime_mark_last_busy(&pci->dev);
> >>> + pm_runtime_put_autosuspend(&pci->dev);
> >>
> >> usually there is a pm_runtime_put_noidle() here?
> >
> > I'm not sure.
> >
> >>
> >> [...]
> >>
> >>> static void snd_rn_acp_remove(struct pci_dev *pci)
> >>> {
> >>> struct acp_dev_data *adata;
> >>> @@ -260,6 +302,9 @@ static void snd_rn_acp_remove(struct pci_dev
> *pci)
> >>> ret = rn_acp_deinit(adata->acp_base);
> >>> if (ret)
> >>> dev_err(&pci->dev, "ACP de-init failed\n");
> >>> + pm_runtime_put_noidle(&pci->dev);
> >>> + pm_runtime_get_sync(&pci->dev);
> >>> + pm_runtime_forbid(&pci->dev);
> >>
> >> doing a put_noidle() followed by a get_sync() and immediately forbid()
> >> is very odd at best.
> >> Isn't the recommendation to call get_noresume() here?
> >>
> >
> > I'm not sure here either. Is there some definitive documentation on
> > what exact sequences are supposed to be used in drivers? A quick
> > browse through drivers that implement runtime pm seems to show a lot
> > of variation. This sequence works. I'm not sure if it's optimal or
> > not.
>
> We based our sequence on the comments in drivers/pci/pci-driver.c
>
> /*
> * Unbound PCI devices are always put in D0, regardless of
> * runtime PM status. During probe, the device is set to
> * active and the usage count is incremented. If the driver
> * supports runtime PM, it should call pm_runtime_put_noidle(),
> * or any other runtime PM helper function decrementing the usage
> * count, in its probe routine and pm_runtime_get_noresume() in
> * its remove routine.
> */
If I understood correctly, below should be the correct sequence rite ?
acp pci driver probe sequence:
pm_runtime_set_autosuspend_delay(&pci->dev, ACP_SUSPEND_DELAY_MS);
pm_runtime_use_autosuspend(&pci->dev);
pm_runtime_put_noidle(&pci->dev);
pm_runtime_allow(&pci->dev);
acp pci driver remove sequence:
pm_runtime_get_noresume(&pci->dev);
pm_runtime_disable(&pci->dev);
I have still have a doubt.
Do we need to call pm_runtime_disable() explicitly in this case ?
