Re: [PATCH] of: property: add i2c-parent to fw_devlink supplier bindings

[Rob Herring <robh@kernel.org>]

On Fri, Aug 14, 2026 at 01:09:49AM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] fw_devlink incorrectly parses I2C slave addresses as phandles due to 0-cell supplier binding definition for `i2c-parent`.
> --
> 
> --- Patch [1]: [PATCH] of: property: add i2c-parent to fw_devlink supplier bindings ---
> commit 85f34a66eac871d9e36bccb6795b94b17ab065d4
> Author: Abdurrahman Hussain <abdurrahman@nexthop.ai>
> 
> of: property: add i2c-parent to fw_devlink supplier bindings
> 
> This commit teaches fw_devlink about i2c-parent so the core creates the
> corresponding device links. This ensures consumers are unbound before the
> parent adapter's device, removing the need for -EPROBE_DEFER.
> 
> > diff --git a/drivers/of/property.c b/drivers/of/property.c
> > --- a/drivers/of/property.c
> > +++ b/drivers/of/property.c
> > @@ -1409,6 +1409,7 @@ DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
> >  DEFINE_SIMPLE_PROP(leds, "leds", NULL)
> >  DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
> >  DEFINE_SIMPLE_PROP(panel, "panel", NULL)
> > +DEFINE_SIMPLE_PROP(i2c_parent, "i2c-parent", NULL)
> 
> [Severity: High]
> Will this correctly handle device tree bindings where the i2c-parent
> property includes a slave address argument?
> 
> For example, platforms using devices like the Toshiba TC9563 PCIe switch
> might use a property such as: i2c-parent = <&qup_i2c 0x77>;
> 
> By passing NULL as the cells argument to DEFINE_SIMPLE_PROP(), the parser
> assumes a 0-cell list. When fw_devlink iterates over the property, it finds
> the first phandle correctly, but won't it erroneously interpret the slave
> address argument (0x77 / 119) as a second, independent 0-cell phandle?
> 
> If another unrelated device tree node happens to match this phandle ID,
> could this cause fw_devlink to link the consumer to the wrong device,
> potentially leading to spurious probe deferrals or circular dependencies?

I think you need custom parsing for this one to read the first cell and 
ignore the 2nd cell if present.

Rob