Re: [PATCH v3 03/12] dt-bindings: i2c: Discard i2c-slave flag from the DW I2C example

From: Serge Semin
Date: Wed May 27 2020 - 08:07:25 EST


On Wed, May 27, 2020 at 12:30:04PM +0300, Andy Shevchenko wrote:
> On Wed, May 27, 2020 at 1:00 AM Serge Semin
> <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > dtc currently doesn't support I2C_OWN_SLAVE_ADDRESS flag set in the
> > i2c "reg" property. If it is the compiler will print a warning:
>
> Shouldn't be dtc whatever tools fixed?

See the first patch in the series.

>
> > Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64: I2C bus unit address format error, expected "40000064"
> > Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64:reg: I2C address must be less than 10-bits, got "0x40000064"
> >
> > In order to silence dtc up let's discard the flag from the DW I2C DT
> > binding example for now. Just revert this commit when dtc is fixed.
>
> Doesn't sound like a good idea. If user happens in between of these
> ping-pong change, how they will know this subtle issue?

As I see it, there are three ways we can follow.
1) Apply the patch and revert when dtc is fixed.
2) Apply the patch, but add a comment above the property, that we need
to get the 0x40000064 address back when dtc is dixed.
3) Leave this ugly warning be until dtc is fixed.

In a comment to v2 Rob mentioned a solution like 1). Personally I am ok with
either, though I'd like to see a Rob's final comment about this.

-Sergey

>
> --
> With Best Regards,
> Andy Shevchenko