Re: [PATCH] ALSA: hda: cs35l56: Perform firmware download in the background

Takashi Iwai
2024-05-02T09:52:30Z

On Thu, 02 May 2024 11:21:36 +0200,
Richard Fitzgerald wrote:
>
> On 02/05/2024 08:34, Takashi Iwai wrote:
> > On Wed, 01 May 2024 13:17:55 +0200,
> > Simon Trimmer wrote:
> >> @@ -964,6 +1011,14 @@ int cs35l56_hda_common_probe(struct cs35l56_hda *cs35l56, int hid, int id)
> >> mutex_init(&cs35l56->base.irq_lock);
> >> dev_set_drvdata(cs35l56->base.dev, cs35l56);
> >> + cs35l56->dsp_wq =
> >> create_singlethread_workqueue("cs35l56-dsp");
> >> + if (!cs35l56->dsp_wq) {
> >> + ret = -ENOMEM;
> >> + goto err;
> >> + }
> >
> > Do we really need a dedicated workqueue? In most usages, simple
> > schedule_work*() works fine and is recommended.
> >
>
> On a slow I2C bus with 4 amps this work could take over 2 seconds.
> That seems too long to be blocking a global system queue. We use a
> dedicated queue in the ASoC driver.
>
> Also if we queue work on an ordered (single-threaded) system queue the
> firmware won't be downloaded to multiple amps in parallel, so we don't
> get the best use of the available bus bandwidth.

OK, that sounds like a sensible argument.

But the patch has no call of a queue destructor. Won't it leak
resources?

thanks,

Takashi