usb: gadget: u_audio: Use managed buffer allocation

Clean up the driver with the new managed buffer allocation API.
The hw_params and hw_free callbacks became superfluous and dropped.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20191210141822.18705-2-tiwai@suse.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/function/u_audio.c

@@ -239,18 +239,6 @@ static snd_pcm_uframes_t uac_pcm_pointer(struct snd_pcm_substream *substream)
 	return bytes_to_frames(substream->runtime, prm->hw_ptr);
 }
 
-static int uac_pcm_hw_params(struct snd_pcm_substream *substream,
-			       struct snd_pcm_hw_params *hw_params)
-{
-	return snd_pcm_lib_malloc_pages(substream,
-					params_buffer_bytes(hw_params));
-}
-
-static int uac_pcm_hw_free(struct snd_pcm_substream *substream)
-{
-	return snd_pcm_lib_free_pages(substream);
-}
-
 static int uac_pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_uac_chip *uac = snd_pcm_substream_chip(substream);
@@ -327,8 +315,6 @@ static const struct snd_pcm_ops uac_pcm_ops = {
 	.open = uac_pcm_open,
 	.close = uac_pcm_null,
 	.ioctl = snd_pcm_lib_ioctl,
-	.hw_params = uac_pcm_hw_params,
-	.hw_free = uac_pcm_hw_free,
 	.trigger = uac_pcm_trigger,
 	.pointer = uac_pcm_pointer,
 	.prepare = uac_pcm_null,
@@ -584,8 +570,8 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
 	strlcpy(card->shortname, card_name, sizeof(card->shortname));
 	sprintf(card->longname, "%s %i", card_name, card->dev->id);
 
-	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
-					      NULL, 0, BUFF_SIZE_MAX);
+	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
+				       NULL, 0, BUFF_SIZE_MAX);
 
 	err = snd_card_register(card);