Re: [alsa-devel] [PATCH v4 08/15] soundwire: add initial definitions for sdw_master_device

[Greg KH]

On Mon, Dec 16, 2019 at 09:02:01AM -0600, Pierre-Louis Bossart wrote:
> 
> 
> On 12/14/19 2:27 AM, Greg KH wrote:
> > On Fri, Dec 13, 2019 at 05:25:23PM -0600, Pierre-Louis Bossart wrote:
> > > 
> > > > No, I mean the new MODULE_NAMESPACE() support that is in the kernel.
> > > > I'll move the greybus code to use it too, but when you are adding new
> > > > apis, it just makes sense to use it then as well.
> > > 
> > > Greg, would the patch below be what you had in mind?
> > > Thanks
> > > -Pierre
> > > 
> > > 
> > > diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
> > > index 76a5c52b12b4..5bad8422887e 100644
> > > --- a/drivers/soundwire/Makefile
> > > +++ b/drivers/soundwire/Makefile
> > > @@ -7,9 +7,11 @@ ccflags-y += -DDEBUG
> > >   #Bus Objs
> > >   soundwire-bus-objs := bus_type.o bus.o master.o slave.o mipi_disco.o
> > > stream.o
> > >   obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o
> > > +ccflags-$(CONFIG_SOUNDWIRE) += -DDEFAULT_SYMBOL_NAMESPACE=SDW_CORE
> > > 
> > >   soundwire-generic-allocation-objs := generic_bandwidth_allocation.o
> > >   obj-$(CONFIG_SOUNDWIRE_GENERIC_ALLOCATION) +=
> > > soundwire-generic-allocation.o
> > > +ccflags-$(CONFIG_SOUNDWIRE_GENERIC_ALLOCATION) +=
> > > -DDEFAULT_SYMBOL_NAMESPACE=SDW_CORE
> > 
> > Don't use ccflags, just use the correct MODULE_EXPORT_NS() tag instead.
> 
> The documentation [1] states
> 
> "
> Defining namespaces for all symbols of a subsystem can be very verbose and
> may become hard to maintain. Therefore a default define
> (DEFAULT_SYMBOL_NAMESPACE) is been provided, that, if set, will become the
> default for all EXPORT_SYMBOL() and EXPORT_SYMBOL_GPL() macro expansions
> that do not specify a namespace.
> "
> 
> If the ccflags option is not supported or no longer desired, it'd be worth
> updating the documentation for dummies like me. I took the wording as a hint
> to avoid using MODULE_EXPORT_NS.

It's supported, and works just fine.  It's just that you really don't
have a ton of exports, right?  What's wrong with manually marking them?

> > And "SDW_CORE" is odd, "SOUNDWIRE" instead?
> 
> 'sdw' is the prefix used everywhere for SoundWire symbols.

Ok, I guess that ship has sailed :(

greg k-h