Re: [PATCH 1/2] ASoC: Intel: maxim-common: get codec number from ACPI

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Mon, Jul 24, 2023 at 11:08:17AM +0200, Pierre-Louis Bossart wrote:
> On 7/20/23 11:26, Brent Lu wrote:

...

> > +/* helper function to get the number of specific codec */

...and leak a lot of reference counts...

> > +static int get_num_codecs(const char *hid)
> > +{
> > +	struct acpi_device *adev = NULL;
> > +	int dev_num = 0;
> > +
> > +	do {
> > +		adev = acpi_dev_get_next_match_dev(adev, hid, NULL, -1);
> 
> Humm, I am a bit worried about reference counts.
> 
> See
> https://elixir.bootlin.com/linux/latest/source/drivers/acpi/utils.c#L916,
> it's not clear to me where the get() is done.
> 
> Adding Andy to make sure this is done right.

Thank you for Cc'ing.

Yes, the above code is problematic. One has to use the respective for_each
macro (defined nearby the used API).

> > +		if (adev)
> > +			dev_num++;
> > +	} while (adev != NULL);
> > +
> > +	return dev_num;
> > +}

-- 
With Best Regards,
Andy Shevchenko