[alsa-devel] [PATCH V2 2/8] ASoC: Samsung: I2S: Add quirks as driver data in I2S

[Russell King - ARM Linux]

On Fri, Jul 26, 2013 at 04:21:16PM +0200, Tomasz Figa wrote:
> Hi Russell,
> 
> On Friday 26 of July 2013 15:06:18 Russell King - ARM Linux wrote:
> > On Fri, Jul 26, 2013 at 07:06:46PM +0530, Padmavathi Venna wrote:
> > > -- compatible : "samsung,i2s-v5"
> > > +- compatible : should be one of the following.
> > > +   - samsung,s3c6410-i2s: for 8/16/24bit stereo I2S. Previous versions
> > > +     has only 8/16bit support.
> > > +   - samsung,s3c6410-i2sv4: for 8/16/24bit multichannel(5.1 channel)
> > > I2S. +     Introduced in s3c6410. This also applicable for s5p64x0
> > > platforms. +   - samsung,s5pc100-i2s: for 8/16/24bit multichannel(5.1
> > > channel) I2S +     with secondary fifo and s/w reset control.
> > > +   - samsung,s5pv210-i2s: for 8/16/24bit multichannel(5.1) I2S with
> > > +     secondary fifo, s/w reset control and internal mux for root clk
> > > src. +
> > 
> > So what happens with your changes to everyone who is using a DT file with
> > the "samsung,i2s-v5" compatible string?
> 
> AFAIK we decided that current bindings, if broken, can be redone correctly, 
> without caring for compatibility with old DTBs and only then, after 
> reviewing these new bindings by DT people, they can be stabilized.
> 
> Other issue, though, is that this patch breaks things until they get fixed 
> by patch 3. Support for new bindings should be added first, then users fixed 
> and only then old bindings can be removed.

So, these bindings were merged in the v3.9 merge window, using the
"samsung,i2s-v5" compatible string, and now for the v3.12 merge window,
you're proposing to break the audio description in any DT file which has
been used with v3.9..v3.11 inclusive?

The way you should be doing this is to keep the existing stuff working
and supplement it with the new method of describing the hardware.