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Date:   Tue, 1 Dec 2020 08:44:21 +0200
From:   Sakari Ailus <sakari.ailus@iki.fi>
To:     Dan Scally <djrscally@gmail.com>
Cc:     linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
        linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org,
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        Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Subject: Re: [PATCH 18/18] ipu3: Add driver for dummy INT3472 ACPI device
Message-ID: <20201201064421.GR4351@valkosipuli.retiisi.org.uk>
References: <20201130133129.1024662-1-djrscally@gmail.com>
 <20201130133129.1024662-19-djrscally@gmail.com>
 <20201130205203.GQ4351@valkosipuli.retiisi.org.uk>
 <3e8494a0-a2c0-59e7-46bb-9635c3c239dd@gmail.com>
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Hi Dan,

On Mon, Nov 30, 2020 at 11:06:03PM +0000, Dan Scally wrote:
> Hi Sakari
> 
> On 30/11/2020 20:52, Sakari Ailus wrote:
> >> +static const struct acpi_device_id int3472_device_id[] = {
> >> +	{ "INT3472", 0 },
> > The INT3472 _HID is really allocated for the tps68470 PMIC chip. It may not
> > be used by other drivers; people will want to build kernels where both of
> > these ACPI table layouts are functional.
> >
> > Instead, I propose, that you add this as an option to the tps68470 driver
> > that figures out whether the ACPI device for the tps68470 device actually
> > describes something else, in a similar fashion you do with the cio2-bridge
> > driver. I think it may need a separate Kconfig option albeit this and
> > cio2-bridge cannot be used separately.
> 
> It actually occurs to me that that may not work (I know I called that
> out as an option we considered, but that was a while ago actually). The
> reason I wasn't worried about the existing tps68470 driver binding to
> these devices is that it's an i2c driver, and these dummy devices don't
> have an I2cSerialBusV2, so no I2C device is created by them the kernel.
> 
> 
> Won't that mean the tps68470 driver won't ever be probed for these devices?

Oops. I missed this indeed was not an I?C driver. So please ignore the
comment.

So I guess this wouldn't be an actual problem. I'd still like to test this
on a system with tps68470, as the rest of the set.

-- 
Kind regards,

Sakari Ailus