Re: [PATCH] i2c: core: helper function to detect slave mode
From: Andy Shevchenko
Date: Thu Jan 12 2017 - 12:06:19 EST
On Sat, 2017-01-07 at 03:24 +0200, Vladimir Zapolskiy wrote:
> On 01/07/2017 02:19 AM, Andy Shevchenko wrote:
> > On Sat, Jan 7, 2017 at 1:43 AM, Vladimir Zapolskiy <vz@xxxxxxxxx>
> > wrote:
> > > On 01/07/2017 12:45 AM, Andy Shevchenko wrote:
> > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ}
> > > > > > +ÂÂÂÂÂ} else if (IS_BUILTIN(CONFIG_ACPI) &&
> > > > > > ACPI_HANDLE(dev)) {
> > > > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂdev_dbg(dev, "ACPI slave is not supported
> > > > > > yet\n");
> > > > > > +ÂÂÂÂÂ}
> > > > >
> > > > > If so, then it might be better to drop else-if stub for now.
> > > >
> > > > Please, don't.
> > > >
> > >
> > > Why do you ask for this stub to be added?
> >
> > 1. Exactly the reason you asked above. Here is the code which has
> > built differently on different platforms. x86 usually is not using
> > CONFIG_OF, ARM doesn't ACPI (versus ARM64). Check GPIO library for
> > existing examples.
>
> From the context by the stub I mean dev_dbg() in
> i2c_slave_mode_detect()
> function, I don't see a connection to GPIO library, please clarify.
I agree that is not good proof for using IS_ENABLED/IS_BUILTIN macro.
> > 2. We might add that support later, but here is again, just no-op.
> >
> > So, what is your strong argument here against that?
>
> When the support is ready for ACPI case, you'll remove the added
> dev_dbg(), and I don't see a good point by adding it temporarily.
It would remind me to look at it at some point.
> What is wrong with the approach of adding the ACPI case handling
> branch when it is ready and remove any kind of stubs right now?
I will not object. Here is maintainer, let him speak.
> On ACPI platforms the function returns 'false' always, will the
> function work correctly (= corresponding to its description) as is?
Yes.
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy