[alsa-devel] [PATCH v4 1/2] ASoC: SOF: introduce no_stream_position so host_period_bytes preserves its data

[Rajwa, Marcin]

From: Marcin Rajwa <marcin.rajwa at linux.intel.com>

Change the use of host_period_bytes. So far this field was used
as an bool value indicating whether FW should send stream position
update. With this patch we use host_period_bytes to provide firmware
information about the frequency of host interrupts aimed to read
its input buffer. This is accoring to ALSA definition of 'FramePeriod'.
Knowing this firmware can safely copy large/irregular chunks of data
(like data comming from i.e draining task) without the risk of buffer
overflow.

Signed-off-by: Marcin Rajwa <marcin.rajwa at linux.intel.com>
Signed-off-by: Keyon Jie <yang.jie at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>

---
  include/sound/sof/stream.h | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/sound/sof/stream.h b/include/sound/sof/stream.h
index 643f175cb479..06af4ecb2584 100644
--- a/include/sound/sof/stream.h
+++ b/include/sound/sof/stream.h
@@ -83,10 +83,10 @@ struct sof_ipc_stream_params {
      uint16_t sample_valid_bytes;
      uint16_t sample_container_bytes;

-    /* for notifying host period has completed - 0 means no period IRQ */
      uint32_t host_period_bytes;
+    uint16_t no_stream_position; /* 1 means no IPC for position update */

-    uint32_t reserved[2];
+    uint16_t reserved[3];
      uint16_t chmap[SOF_IPC_MAX_CHANNELS];    /**< channel map - 
SOF_CHMAP_ */
  } __packed;