ALSA: hda: Add dma stop delay variable

A variable dma_stop_delay is added as a new member in hdac_bus structure to avoid memory decode error incase DMA RUN bit is not disabled in the given timeout from snd_hdac_stream_sync function and followed by stream reset which results in memory decode error between reset set and clear operation. Signed-off-by: Mohan Kumar <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Takashi Iwai <[email protected]>
vieko · Aug 5, 2020 · 4106820 · 4106820
1 parent 6c17e9d
commit 4106820
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 0 deletions.
diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h
@@ -347,6 +347,9 @@ struct hdac_bus {
 
 	int bdl_pos_adj;		/* BDL position adjustment */
 
+	/* delay time in us for dma stop */
+	unsigned int dma_stop_delay;
+
 	/* locks */
 	spinlock_t reg_lock;
 	struct mutex cmd_mutex;

diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c
@@ -150,9 +150,12 @@ void snd_hdac_stream_reset(struct hdac_stream *azx_dev)
 {
 	unsigned char val;
 	int timeout;
+	int dma_run_state;
 
 	snd_hdac_stream_clear(azx_dev);
 
+	dma_run_state = snd_hdac_stream_readb(azx_dev, SD_CTL) & SD_CTL_DMA_START;
+
 	snd_hdac_stream_updateb(azx_dev, SD_CTL, 0, SD_CTL_STREAM_RESET);
 	udelay(3);
 	timeout = 300;
@@ -162,6 +165,10 @@ void snd_hdac_stream_reset(struct hdac_stream *azx_dev)
 		if (val)
 			break;
 	} while (--timeout);
+
+	if (azx_dev->bus->dma_stop_delay && dma_run_state)
+		udelay(azx_dev->bus->dma_stop_delay);
+
 	val &= ~SD_CTL_STREAM_RESET;
 	snd_hdac_stream_writeb(azx_dev, SD_CTL, val);
 	udelay(3);