ALSA: caiaq: Use managed buffer allocation

Clean up the driver with the new managed buffer allocation API.
The hw_params callback became superfluous and dropped.
The hw_free callback still remains because of the substream
deactivation sync call.

Link: https://lore.kernel.org/r/20191209094943.14984-66-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/caiaq/audio.c

@@ -167,17 +167,11 @@ static int snd_usb_caiaq_substream_close(struct snd_pcm_substream *substream)
 	return 0;
 }
 
-static int snd_usb_caiaq_pcm_hw_params(struct snd_pcm_substream *sub,
-				       struct snd_pcm_hw_params *hw_params)
-{
-	return snd_pcm_lib_malloc_pages(sub, params_buffer_bytes(hw_params));
-}
-
 static int snd_usb_caiaq_pcm_hw_free(struct snd_pcm_substream *sub)
 {
 	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(sub);
 	deactivate_substream(cdev, sub);
-	return snd_pcm_lib_free_pages(sub);
+	return 0;
 }
 
 /* this should probably go upstream */
@@ -328,7 +322,6 @@ static const struct snd_pcm_ops snd_usb_caiaq_ops = {
 	.open =		snd_usb_caiaq_substream_open,
 	.close =	snd_usb_caiaq_substream_close,
 	.ioctl =	snd_pcm_lib_ioctl,
-	.hw_params =	snd_usb_caiaq_pcm_hw_params,
 	.hw_free =	snd_usb_caiaq_pcm_hw_free,
 	.prepare =	snd_usb_caiaq_pcm_prepare,
 	.trigger =	snd_usb_caiaq_pcm_trigger,
@@ -841,7 +834,7 @@ int snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *cdev)
 				&snd_usb_caiaq_ops);
 	snd_pcm_set_ops(cdev->pcm, SNDRV_PCM_STREAM_CAPTURE,
 				&snd_usb_caiaq_ops);
-	snd_pcm_lib_preallocate_pages_for_all(cdev->pcm, SNDRV_DMA_TYPE_VMALLOC,
+	snd_pcm_set_managed_buffer_all(cdev->pcm, SNDRV_DMA_TYPE_VMALLOC,
 				       NULL, 0, 0);
 
 	cdev->data_cb_info =