ALSA: pci: rme: Fix unaligned buffer addresses

The recent fix for setting up the DMA buffer type on RME drivers tried
to address the non-standard memory managements and changed the DMA
buffer information to the standard snd_dma_buffer object that is
allocated at the probe time.  However, I overlooked that the RME
drivers handle the buffer addresses based on 64k alignment, and the
previous conversion broke that silently.

This patch is an attempt to fix the regression.  The snd_dma_buffer
objects are copied to the original data with the correction to the
aligned accesses, and those are passed to snd_pcm_set_runtime_buffer()
helpers instead.  The original snd_dma_buffer objects are managed by
devres, hence they'll be released automagically.

Fixes: 0899a7a23047 ("ALSA: pci: rme: Set up buffer type properly")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211108145752.30572-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 23 insertions, 18 deletions

diff --git a/sound/pci/rme9652/hdsp.c b/sound/pci/rme9652/hdsp.c
index 75aa2ea733a5..96c12dfb24cf 100644
--- a/sound/pci/rme9652/hdsp.c
+++ b/sound/pci/rme9652/hdsp.c
@@ -468,8 +468,11 @@ struct hdsp {
 	unsigned char         ss_out_channels;
 	u32                   io_loopback;          /* output loopback channel states*/
 
-	struct snd_dma_buffer *capture_dma_buf;
-	struct snd_dma_buffer *playback_dma_buf;
+	/* DMA buffers; those are copied instances from the original snd_dma_buf
+	 * objects (which are managed via devres) for the address alignments
+	 */
+	struct snd_dma_buffer capture_dma_buf;
+	struct snd_dma_buffer playback_dma_buf;
 	unsigned char        *capture_buffer;	    /* suitably aligned address */
 	unsigned char        *playback_buffer;	    /* suitably aligned address */
 
@@ -3764,30 +3767,32 @@ static void snd_hdsp_proc_init(struct hdsp *hdsp)
 
 static int snd_hdsp_initialize_memory(struct hdsp *hdsp)
 {
-	unsigned long pb_bus, cb_bus;
+	struct snd_dma_buffer *capture_dma, *playback_dma;
 
-	hdsp->capture_dma_buf =
-		snd_hammerfall_get_buffer(hdsp->pci, HDSP_DMA_AREA_BYTES);
-	hdsp->playback_dma_buf =
-		snd_hammerfall_get_buffer(hdsp->pci, HDSP_DMA_AREA_BYTES);
-	if (!hdsp->capture_dma_buf || !hdsp->playback_dma_buf) {
+	capture_dma = snd_hammerfall_get_buffer(hdsp->pci, HDSP_DMA_AREA_BYTES);
+	playback_dma = snd_hammerfall_get_buffer(hdsp->pci, HDSP_DMA_AREA_BYTES);
+	if (!capture_dma || !playback_dma) {
 		dev_err(hdsp->card->dev,
 			"%s: no buffers available\n", hdsp->card_name);
 		return -ENOMEM;
 	}
 
-	/* Align to bus-space 64K boundary */
+	/* copy to the own data for alignment */
+	hdsp->capture_dma_buf = *capture_dma;
+	hdsp->playback_dma_buf = *playback_dma;
 
-	cb_bus = ALIGN(hdsp->capture_dma_buf->addr, 0x10000ul);
-	pb_bus = ALIGN(hdsp->playback_dma_buf->addr, 0x10000ul);
+	/* Align to bus-space 64K boundary */
+	hdsp->capture_dma_buf.addr = ALIGN(capture_dma->addr, 0x10000ul);
+	hdsp->playback_dma_buf.addr = ALIGN(playback_dma->addr, 0x10000ul);
 
 	/* Tell the card where it is */
+	hdsp_write(hdsp, HDSP_inputBufferAddress, hdsp->capture_dma_buf.addr);
+	hdsp_write(hdsp, HDSP_outputBufferAddress, hdsp->playback_dma_buf.addr);
 
-	hdsp_write(hdsp, HDSP_inputBufferAddress, cb_bus);
-	hdsp_write(hdsp, HDSP_outputBufferAddress, pb_bus);
-
-	hdsp->capture_buffer = hdsp->capture_dma_buf->area + (cb_bus - hdsp->capture_dma_buf->addr);
-	hdsp->playback_buffer = hdsp->playback_dma_buf->area + (pb_bus - hdsp->playback_dma_buf->addr);
+	hdsp->capture_dma_buf.area += hdsp->capture_dma_buf.addr - capture_dma->addr;
+	hdsp->playback_dma_buf.area += hdsp->playback_dma_buf.addr - playback_dma->addr;
+	hdsp->capture_buffer = hdsp->capture_dma_buf.area;
+	hdsp->playback_buffer = hdsp->playback_dma_buf.area;
 
 	return 0;
 }
@@ -4507,7 +4512,7 @@ static int snd_hdsp_playback_open(struct snd_pcm_substream *substream)
 	snd_pcm_set_sync(substream);
 
         runtime->hw = snd_hdsp_playback_subinfo;
-	snd_pcm_set_runtime_buffer(substream, hdsp->playback_dma_buf);
+	snd_pcm_set_runtime_buffer(substream, &hdsp->playback_dma_buf);
 
 	hdsp->playback_pid = current->pid;
 	hdsp->playback_substream = substream;
@@ -4583,7 +4588,7 @@ static int snd_hdsp_capture_open(struct snd_pcm_substream *substream)
 	snd_pcm_set_sync(substream);
 
 	runtime->hw = snd_hdsp_capture_subinfo;
-	snd_pcm_set_runtime_buffer(substream, hdsp->capture_dma_buf);
+	snd_pcm_set_runtime_buffer(substream, &hdsp->capture_dma_buf);
 
 	hdsp->capture_pid = current->pid;
 	hdsp->capture_substream = substream;