ALSA: pci: cs46xx: Fix set up buffer type properly

commit 4d9e915 upstream.

CS46xx driver switches the buffer depending on the number of periods,
and in some cases it switches to the own buffer without updating the
buffer type properly.  This may cause a problem with the mmap on
exotic architectures that require the own mmap call for the coherent
DMA buffer.

This patch addresses the potential breakage by replacing the buffer
setup with the proper macro.  It also simplifies the source code,
too.

Link: https://lore.kernel.org/r/20210809071829.22238-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sound/pci/cs46xx/cs46xx_lib.c

@@ -1121,9 +1121,7 @@ static int snd_cs46xx_playback_hw_params(struct snd_pcm_substream *substream,
 	if (params_periods(hw_params) == CS46XX_FRAGS) {
 		if (runtime->dma_area != cpcm->hw_buf.area)
 			snd_pcm_lib_free_pages(substream);
-		runtime->dma_area = cpcm->hw_buf.area;
-		runtime->dma_addr = cpcm->hw_buf.addr;
-		runtime->dma_bytes = cpcm->hw_buf.bytes;
+		snd_pcm_set_runtime_buffer(substream, &cpcm->hw_buf);
 
 
 #ifdef CONFIG_SND_CS46XX_NEW_DSP
@@ -1143,11 +1141,8 @@ static int snd_cs46xx_playback_hw_params(struct snd_pcm_substream *substream,
 #endif
 
 	} else {
-		if (runtime->dma_area == cpcm->hw_buf.area) {
-			runtime->dma_area = NULL;
-			runtime->dma_addr = 0;
-			runtime->dma_bytes = 0;
-		}
+		if (runtime->dma_area == cpcm->hw_buf.area)
+			snd_pcm_set_runtime_buffer(substream, NULL);
 		err = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
 		if (err < 0) {
 #ifdef CONFIG_SND_CS46XX_NEW_DSP
@@ -1196,9 +1191,7 @@ static int snd_cs46xx_playback_hw_free(struct snd_pcm_substream *substream)
 	if (runtime->dma_area != cpcm->hw_buf.area)
 		snd_pcm_lib_free_pages(substream);
 
-	runtime->dma_area = NULL;
-	runtime->dma_addr = 0;
-	runtime->dma_bytes = 0;
+	snd_pcm_set_runtime_buffer(substream, NULL);
 
 	return 0;
 }
@@ -1287,16 +1280,11 @@ static int snd_cs46xx_capture_hw_params(struct snd_pcm_substream *substream,
 	if (runtime->periods == CS46XX_FRAGS) {
 		if (runtime->dma_area != chip->capt.hw_buf.area)
 			snd_pcm_lib_free_pages(substream);
-		runtime->dma_area = chip->capt.hw_buf.area;
-		runtime->dma_addr = chip->capt.hw_buf.addr;
-		runtime->dma_bytes = chip->capt.hw_buf.bytes;
+		snd_pcm_set_runtime_buffer(substream, &chip->capt.hw_buf);
 		substream->ops = &snd_cs46xx_capture_ops;
 	} else {
-		if (runtime->dma_area == chip->capt.hw_buf.area) {
-			runtime->dma_area = NULL;
-			runtime->dma_addr = 0;
-			runtime->dma_bytes = 0;
-		}
+		if (runtime->dma_area == chip->capt.hw_buf.area)
+			snd_pcm_set_runtime_buffer(substream, NULL);
 		err = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
 		if (err < 0)
 			return err;
@@ -1313,9 +1301,7 @@ static int snd_cs46xx_capture_hw_free(struct snd_pcm_substream *substream)
 
 	if (runtime->dma_area != chip->capt.hw_buf.area)
 		snd_pcm_lib_free_pages(substream);
-	runtime->dma_area = NULL;
-	runtime->dma_addr = 0;
-	runtime->dma_bytes = 0;
+	snd_pcm_set_runtime_buffer(substream, NULL);
 
 	return 0;
 }