[PATCH] ALSA: cs46xx: Fix possible mmap breakage

[Takashi Iwai]

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 due to the recent
introduced more strict mmap buffer check.

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

Fixes: c4824ae7db41 ("ALSA: pcm: Fix mmap capability check")
Cc: <stable at vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/pci/cs46xx/cs46xx_lib.c | 30 ++++++++----------------------
 1 file changed, 8 insertions(+), 22 deletions(-)

diff --git a/sound/pci/cs46xx/cs46xx_lib.c b/sound/pci/cs46xx/cs46xx_lib.c
index 1e1eb17f8e07..d43927dcd61e 100644
--- a/sound/pci/cs46xx/cs46xx_lib.c
+++ b/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;
 }
-- 
2.26.2