Re: [RESEND PATCH v4 0/8] i2c: Relax mandatory I2C ID table passing

From: Wolfram Sang
Date: Thu Oct 01 2015 - 16:50:46 EST



> > Yes but that is not true for drivers that support both OF and legacy board
> > files. For those drivers, there will be a lot of boiler plate code duplicated
> > that would look something like:
> >
> > unsigned long data;
> > struct of_device_id *match;
> > struct i2c_devicd_id *id;
> >
> > if (i2c->dev.of_node) {
> > match = i2c_of_match_device(of_match_table, i2c);
> > if (!match)
> > return -EINVAL;
> >
> > data = (unsigned long)match->data;
> > } else {
> > id = i2c_match_id(id_table, i2c);
> > if (!id)
> > return -EINVAL;
> >
> > data = id->driver_data;
> > }

I said this before: It is not only the additional code, I think it is
quite unelegant to to do the matching again which has already been done.
(and DT boottime has already increased, partly due to the excessive
string matching). Also, I wouldn't like to see an I2C specific solution;
this problem exists for other subsystems, too.

> I'm fine with a new API for this stuff. I'm even happy to go ahead
> and code it up, but it's important to note that this is work which
> should be based on this set and not a blocker for this set to be
> accepted.

Is that a promise? :)

> The correct approach is the former. One of the aims of this set was
> to bring the I2C .probe() call-back more into line with the majority
> of the other .probe() calls in the kernel i.e. with only a single
> parameter. I'm really not a fan of passing some random void pointer

Yes, I like this about this series.

> in. Using a look-up call to fetch ACPI/OF/I2C/etc data is the current
> norm and is a very viable option.

It is the status quo, but that doesn't make it better IMO.

> Wolfram, please (finally :D) take this set.

I tend to give in ;) Maybe we can talk in Dublin a bit about a possible
next step after this series?

Thanks,

Wolfram

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