Re: [alsa-devel] [PATCH v2] soundwire: Make slave.o depend on ACPI and rename to acpi_slave.o

[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 <natechancellor@xxxxxxxxx>

Sounds good, thanks for the fix.

Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

> ---
>
> 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
> @@ -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