[PATCH] soundwire: Don't build sound.o without CONFIG_ACPI

[Nathan Chancellor]

clang warns when CONFIG_ACPI is unset:

../drivers/soundwire/slave.c:16:12: warning: unused function
'sdw_slave_add' [-Wunused-function]
static int sdw_slave_add(struct sdw_bus *bus,
^
1 warning generated.

Before commit 8676b3ca4673 ("soundwire: fix regmap dependencies and
align with other serial links"), this code would only be compiled when
ACPI was set because it was only selected by SOUNDWIRE_INTEL, which
depends on ACPI.

Now, this code can be compiled without CONFIG_ACPI, which causes the
above warning. The IS_ENABLED(CONFIG_ACPI) guard could be moved to avoid
compiling the function; however, slave.c only contains three functions,
two of which are static. Only compile slave.o when CONFIG_ACPI is set,
where it will actually be used. bus.h contains a stub for
sdw_acpi_find_slaves so there will be no issues with an undefined
function.

This has been build tested with CONFIG_ACPI set and unset in combination
with CONFIG_SOUNDWIRE unset, built in, and a module.

Fixes: 8676b3ca4673 ("soundwire: fix regmap dependencies and align with other serial links")
Link: https://github.com/ClangBuiltLinux/linux/issues/637
Signed-off-by: Nathan Chancellor <natecha...@gmail.com>
---
drivers/soundwire/Makefile | 6 +++++-
drivers/soundwire/slave.c | 3 ---
2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index 45b7e5001653..226090902716 100644
--- a/drivers/soundwire/Makefile
+++ b/drivers/soundwire/Makefile
@@ -4,9 +4,13 @@
#

#Bus Objs
-soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o
+soundwire-bus-objs := bus_type.o bus.o mipi_disco.o stream.o
obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o

+ifdef CONFIG_ACPI
+soundwire-bus-objs += slave.o
+endif
+
#Cadence Objs
soundwire-cadence-objs := cadence_master.o
obj-$(CONFIG_SOUNDWIRE_CADENCE) += soundwire-cadence.o
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index f39a5815e25d..0dc188e6873b 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -60,7 +60,6 @@ static int sdw_slave_add(struct sdw_bus *bus,
return ret;
}

-#if IS_ENABLED(CONFIG_ACPI)
/*
* sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
* @bus: SDW bus instance
@@ -110,5 +109,3 @@ int sdw_acpi_find_slaves(struct sdw_bus *bus)

return 0;
}
-
-#endif
--
2.23.0.rc2

[Pierre-Louis Bossart]

On 8/13/19 1:10 AM, Nathan Chancellor wrote:
> clang warns when CONFIG_ACPI is unset:
>
> ../drivers/soundwire/slave.c:16:12: warning: unused function
> 'sdw_slave_add' [-Wunused-function]
> static int sdw_slave_add(struct sdw_bus *bus,
> ^
> 1 warning generated.
>
> Before commit 8676b3ca4673 ("soundwire: fix regmap dependencies and
> align with other serial links"), this code would only be compiled when
> ACPI was set because it was only selected by SOUNDWIRE_INTEL, which
> depends on ACPI.
>
> Now, this code can be compiled without CONFIG_ACPI, which causes the
> above warning. The IS_ENABLED(CONFIG_ACPI) guard could be moved to avoid
> compiling the function; however, slave.c only contains three functions,
> two of which are static. Only compile slave.o when CONFIG_ACPI is set,
> where it will actually be used. bus.h contains a stub for
> sdw_acpi_find_slaves so there will be no issues with an undefined
> function.
>
> This has been build tested with CONFIG_ACPI set and unset in combination
> with CONFIG_SOUNDWIRE unset, built in, and a module.

Thanks for the patch. Do you have a .config you can share offline so
that we add it to our tests?

>
> Fixes: 8676b3ca4673 ("soundwire: fix regmap dependencies and align with other serial links")
> Link: https://github.com/ClangBuiltLinux/linux/issues/637
> Signed-off-by: Nathan Chancellor <natecha...@gmail.com>
> ---
> drivers/soundwire/Makefile | 6 +++++-
> drivers/soundwire/slave.c | 3 ---
> 2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
> index 45b7e5001653..226090902716 100644
> --- a/drivers/soundwire/Makefile
> +++ b/drivers/soundwire/Makefile
> @@ -4,9 +4,13 @@
> #
>
> #Bus Objs
> -soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o
> +soundwire-bus-objs := bus_type.o bus.o mipi_disco.o stream.o
> obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o
>
> +ifdef CONFIG_ACPI
> +soundwire-bus-objs += slave.o
> +endif

I am fine with the change, but we might as well rename the file
acpi_slave.c then?

[Nathan Chancellor]

On Tue, Aug 13, 2019 at 09:22:29AM -0500, Pierre-Louis Bossart wrote:
> On 8/13/19 1:10 AM, Nathan Chancellor wrote:
> > clang warns when CONFIG_ACPI is unset:
> >
> > ../drivers/soundwire/slave.c:16:12: warning: unused function
> > 'sdw_slave_add' [-Wunused-function]
> > static int sdw_slave_add(struct sdw_bus *bus,
> > ^
> > 1 warning generated.
> >
> > Before commit 8676b3ca4673 ("soundwire: fix regmap dependencies and
> > align with other serial links"), this code would only be compiled when
> > ACPI was set because it was only selected by SOUNDWIRE_INTEL, which
> > depends on ACPI.
> >
> > Now, this code can be compiled without CONFIG_ACPI, which causes the
> > above warning. The IS_ENABLED(CONFIG_ACPI) guard could be moved to avoid
> > compiling the function; however, slave.c only contains three functions,
> > two of which are static. Only compile slave.o when CONFIG_ACPI is set,
> > where it will actually be used. bus.h contains a stub for
> > sdw_acpi_find_slaves so there will be no issues with an undefined
> > function.
> >
> > This has been build tested with CONFIG_ACPI set and unset in combination
> > with CONFIG_SOUNDWIRE unset, built in, and a module.
>
> Thanks for the patch. Do you have a .config you can share offline so that we
> add it to our tests?

I just took the arm64 defconfig and deleted CONFIG_ACPI and added
CONFIG_SOUNDWIRE=y or =m to produce this warning. I initially found this
on an arm64 allyesconfig build.

>
> >
> > Fixes: 8676b3ca4673 ("soundwire: fix regmap dependencies and align with other serial links")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/637
> > Signed-off-by: Nathan Chancellor <natecha...@gmail.com>
> > ---
> > drivers/soundwire/Makefile | 6 +++++-
> > drivers/soundwire/slave.c | 3 ---
> > 2 files changed, 5 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
> > index 45b7e5001653..226090902716 100644
> > --- a/drivers/soundwire/Makefile
> > +++ b/drivers/soundwire/Makefile
> > @@ -4,9 +4,13 @@
> > #
> > #Bus Objs
> > -soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o
> > +soundwire-bus-objs := bus_type.o bus.o mipi_disco.o stream.o
> > obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o
> > +ifdef CONFIG_ACPI
> > +soundwire-bus-objs += slave.o
> > +endif
>
> I am fine with the change, but we might as well rename the file acpi_slave.c
> then?

Sure, I can do that rename and send a v2.

[Nathan Chancellor]

clang warns when CONFIG_ACPI is unset:

../drivers/soundwire/slave.c:16:12: warning: unused function
'sdw_slave_add' [-Wunused-function]
static int sdw_slave_add(struct sdw_bus *bus,
^
1 warning generated.

Before commit 8676b3ca4673 ("soundwire: fix regmap dependencies and
align with other serial links"), this code would only be compiled when
ACPI was set because it was only selected by SOUNDWIRE_INTEL, which
depends on ACPI.

Now, this code can be compiled without CONFIG_ACPI, which causes the
above warning. The IS_ENABLED(CONFIG_ACPI) guard could be moved to avoid
compiling the function; however, slave.c only contains three functions,

two of which are static. Since slave.c is completetely dependent on
ACPI, rename it to acpi_slave.c and only compile it when CONFIG_ACPI
is set so sdw_acpi_find_slaves will actually be used. bus.h contains

a stub for sdw_acpi_find_slaves so there will be no issues with an
undefined function.

This has been build tested with CONFIG_ACPI set and unset in combination
with CONFIG_SOUNDWIRE unset, built in, and a module.

Fixes: 8676b3ca4673 ("soundwire: fix regmap dependencies and align with other serial links")
Link: https://github.com/ClangBuiltLinux/linux/issues/637
Signed-off-by: Nathan Chancellor <natecha...@gmail.com>
---

v1 -> v2:

* Rename slave.o to acpi_slave.o
* Reword commit message to reflect this

drivers/soundwire/Makefile | 6 +++++-
drivers/soundwire/{slave.c => acpi_slave.c} | 3 ---

2 files changed, 5 insertions(+), 4 deletions(-)

rename drivers/soundwire/{slave.c => acpi_slave.c} (98%)

diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index 45b7e5001653..718d8dd0ac79 100644

--- a/drivers/soundwire/Makefile
+++ b/drivers/soundwire/Makefile
@@ -4,9 +4,13 @@
#

#Bus Objs
-soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o stream.o
+soundwire-bus-objs := bus_type.o bus.o mipi_disco.o stream.o
obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o

+ifdef CONFIG_ACPI

+soundwire-bus-objs += acpi_slave.o

+endif
+
#Cadence Objs
soundwire-cadence-objs := cadence_master.o
obj-$(CONFIG_SOUNDWIRE_CADENCE) += soundwire-cadence.o

diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/acpi_slave.c
similarity index 98%
rename from drivers/soundwire/slave.c
rename to drivers/soundwire/acpi_slave.c

index f39a5815e25d..0dc188e6873b 100644
--- a/drivers/soundwire/slave.c

+++ b/drivers/soundwire/acpi_slave.c

[Nick Desaulniers]

Looks good, thanks Nathan.
Reviewed-by: Nick Desaulniers <ndesau...@google.com>

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--
Thanks,
~Nick Desaulniers

[Pierre-Louis Bossart]

On 8/13/19 1:09 PM, Nathan Chancellor wrote:
> clang warns when CONFIG_ACPI is unset:
>
> ../drivers/soundwire/slave.c:16:12: warning: unused function
> 'sdw_slave_add' [-Wunused-function]
> static int sdw_slave_add(struct sdw_bus *bus,
> ^
> 1 warning generated.
>
> Before commit 8676b3ca4673 ("soundwire: fix regmap dependencies and
> align with other serial links"), this code would only be compiled when
> ACPI was set because it was only selected by SOUNDWIRE_INTEL, which
> depends on ACPI.
>
> Now, this code can be compiled without CONFIG_ACPI, which causes the
> above warning. The IS_ENABLED(CONFIG_ACPI) guard could be moved to avoid
> compiling the function; however, slave.c only contains three functions,
> two of which are static. Since slave.c is completetely dependent on
> ACPI, rename it to acpi_slave.c and only compile it when CONFIG_ACPI
> is set so sdw_acpi_find_slaves will actually be used. bus.h contains
> a stub for sdw_acpi_find_slaves so there will be no issues with an
> undefined function.
>
> This has been build tested with CONFIG_ACPI set and unset in combination
> with CONFIG_SOUNDWIRE unset, built in, and a module.
>
> Fixes: 8676b3ca4673 ("soundwire: fix regmap dependencies and align with other serial links")
> Link: https://github.com/ClangBuiltLinux/linux/issues/637
> Signed-off-by: Nathan Chancellor <natecha...@gmail.com>

Sounds good, thanks for the fix.

Acked-by: Pierre-Louis Bossart <pierre-lou...@linux.intel.com>

[Vinod Koul]

Srini's change add support for DT for the same file, so It does not make
sense to rename. Yes this patch tries to fix a warn which is there due
to DT being not supported but with Srini's patches this warn should go
away as sdw_slave_add() will be invoked by the DT counterpart

Sorry Nathan, we would have to live with the warn for few more days till
I apply Srini's changes. So I am not taking this (or v2) patch

Thanks

>
> > +
> > #Cadence Objs
> > soundwire-cadence-objs := cadence_master.o
> > obj-$(CONFIG_SOUNDWIRE_CADENCE) += soundwire-cadence.o
> > diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
> > index f39a5815e25d..0dc188e6873b 100644
> > --- a/drivers/soundwire/slave.c
> > +++ b/drivers/soundwire/slave.c
> > @@ -60,7 +60,6 @@ static int sdw_slave_add(struct sdw_bus *bus,
> > return ret;
> > }
> > -#if IS_ENABLED(CONFIG_ACPI)
> > /*
> > * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
> > * @bus: SDW bus instance
> > @@ -110,5 +109,3 @@ int sdw_acpi_find_slaves(struct sdw_bus *bus)
> > return 0;
> > }
> > -
> > -#endif
> >

--
~Vinod

[Nathan Chancellor]

That is fine as I can apply this locally. Could you point me to these
patches so that I can take a look at them?

Thanks for the reply!
Nathan

[Vinod Koul]

Here you go:

https://lore.kernel.org/lkml/20190808144504.24823-...@linaro.org/

--
~Vinod