Re: [PATCH 2/2] mfd: intel-lpss: Add "linux,use-dynamic-adapter-nr" device-prop to i2c-devices

[Wolfram Sang]

On Mon, Mar 11, 2019 at 12:22:16PM +0100, Hans de Goede wrote:
> The i2c-designware-platdrv assumes that if the pdev has an apci-companion
> it should use a dynamic adapter-nr and otherwise it will use pdev->id as
> adapter-nr.
> 
> On some devices e.g. the Apollo Lake using Acer TravelMate Spin B118,
> some of the LPSS i2c-adapters are enumerated through PCI and do not have
> an ACPI fwnode. These devices are handled as mfd devices so they end up
> using the i2c-designware-platdrv driver.
> 
> This results in the i2c-adapter being registered with the mfd generated
> pdev->id as adapter-nr, which conflicts with existing adapters, triggering
> a WARN(id < 0, "couldn't get idr") in i2c-core-base.c and causing the
> adapter registration to fail.
> 
> To fix this the i2c-designware-platdrv now also supports a
> "linux,use-dynamic-adapter-nr" device-property, which tells it to use a
> dynamic adapter nr even if there is no ACPI fwnode for the device.
> 
> This commit adds this device-property to the properties list for PCI
> enumerated LPSS i2c-adapters.
> 
> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1687065
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>

You need to CC the devicetree ML on such patches. However, I am afraid I
can pretty much NACK this one already. This is a Linux configuration
item and DT is only for describing HW.

Maybe the designware maintainers have a better idea how to achieve what
you need.

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