@@ -21,6 +21,7 @@
#include <linux/pci.h>
#include <linux/pm_runtime.h>
+#include <linux/delay.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include "skl.h"
@@ -1063,13 +1064,31 @@ static snd_pcm_uframes_t skl_platform_pcm_pointer
* HAD space reflects the actual data that is transferred.
* Use the position buffer for capture, as DPIB write gets
* completed earlier than the actual data written to the DDR.
+ *
+ * For capture stream following workaround is required to fix the
+ * incorrect position reporting.
+ *
+ * 1. Wait for 20us before reading the DMA position in buffer once
+ * the interrupt is generated for stream completion as update happens
+ * on the HDA frame boundary i.e. 20.833uSec.
+ * 2. Read DPIB register to flush the DMA position value. This dummy
+ * read is required to flush DMA position value.
+ * 3. Read the DMA Position-in-Buffer. This value now will be equal to
+ * or greater than period boundary.
*/
- if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
pos = readl(ebus->bus.remap_addr + AZX_REG_VS_SDXDPIB_XBASE +
(AZX_REG_VS_SDXDPIB_XINTERVAL *
hdac_stream(hstream)->index));
- else
+ } else {
+ udelay(20);
+ readl(ebus->bus.remap_addr +
+ AZX_REG_VS_SDXDPIB_XBASE +
+ (AZX_REG_VS_SDXDPIB_XINTERVAL *
+ hdac_stream(hstream)->index));
pos = snd_hdac_stream_get_pos_posbuf(hdac_stream(hstream));
+ }
if (pos >= hdac_stream(hstream)->bufsize)
pos = 0;