usb: gadget: build audio_source function only if SND is enabled

Also select SND_PCM while building f_audio_source
otherwise we run into following build error:

  LD      init/built-in.o
drivers/built-in.o: In function `audio_data_complete':
/linaro/android/kernel/linaro-android/drivers/usb/gadget/function/f_audio_source.c:458: undefined reference to `snd_pcm_period_elapsed'
drivers/built-in.o: In function `audio_pcm_hw_free':
/linaro/android/kernel/linaro-android/drivers/usb/gadget/function/f_audio_source.c:770: undefined reference to `snd_pcm_lib_free_vmalloc_buffer'
drivers/built-in.o: In function `snd_pcm_lib_alloc_vmalloc_buffer':
/linaro/android/kernel/linaro-android/include/sound/pcm.h:1179: undefined reference to `_snd_pcm_lib_alloc_vmalloc_buffer'
drivers/built-in.o: In function `audio_pcm_open':
/linaro/android/kernel/linaro-android/drivers/usb/gadget/function/f_audio_source.c:734: undefined reference to `snd_pcm_limit_hw_rates'
drivers/built-in.o: In function `snd_card_setup':
/linaro/android/kernel/linaro-android/drivers/usb/gadget/function/f_audio_source.c:888: undefined reference to `snd_pcm_new'
/linaro/android/kernel/linaro-android/drivers/usb/gadget/function/f_audio_source.c:898: undefined reference to `snd_pcm_set_ops'
/linaro/android/kernel/linaro-android/drivers/usb/gadget/function/f_audio_source.c:899: undefined reference to `snd_pcm_lib_preallocate_pages_for_all'
drivers/built-in.o:(.data+0x1fd28): undefined reference to `snd_pcm_lib_ioctl'
make: *** [vmlinux] Error 1

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 221f2c50d7e274050d82066972885d147a2e75b0..5cf6802b02ae72987146734461f43570a355bf46 100644 (file)
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -407,6 +407,8 @@ config USB_CONFIGFS_F_ACC
 config USB_CONFIGFS_F_AUDIO_SRC
        boolean "Audio Source gadget"
        depends on USB_CONFIGFS && USB_CONFIGFS_F_ACC
+       depends on SND
+       select SND_PCM
        select USB_F_AUDIO_SRC
        help
          USB gadget Audio Source support