Re: [PATCH v6 07/10] hda: cs35l41: Add support for CS35L41 in HDA systems

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Sorry for resurrecting old thread...

On Thu, Jan 06, 2022 at 02:29:58PM +0200, Andy Shevchenko wrote:
> On Fri, Dec 17, 2021 at 5:45 PM Lucas Tanure
> <tanureal@opensource.cirrus.com> wrote:
> >
> > Add support for CS35L41 using a new separated driver
> > that can be used in all upcoming designs

...

> > +       /* No devm_ version as CLSA0100, in no_acpi_dsd case, can't use devm version */
> 
> Can you elaborate why devm can't be used?
> 
> > +       cs35l41->reset_gpio = fwnode_gpiod_get_index(&adev->fwnode, "reset", cs35l41->index,
> 
> Please, do not dereference fwnode pointers.
> Also, why can't you use the device instead of fwnode?

We are doing "acpi_dev_put(adev);" a few lines above, so using adev in
the call to fwnode_gpiod_get_index() is technically use-after-free,
isn't it?

Also, why can't we do

	cs35l41->reset_gpio = gpiod_get_index(acpi_dev, "reset",
					      cs35l41->index,
					      GPIOD_OUT_LOW);

since acpi_dev is device structure corresponding to adev and we are
getting the rest of the properties from it?

I saw downthread that there was supposed to be a patch addressing
several issues raised by Andy, was it ever submitted?

Thanks.

-- 
Dmitry