[PATCH 0/7] ASoC/soundwire: add fake BPT frame to align Intel DMA buffer size

[PATCH 0/7] ASoC/soundwire: add fake BPT frame to align Intel DMA buffer size

[Bard Liao]

There is a constraint on Intel DMA buffer size that needs to be a
multiple of data block size. This series adds some fake BRA frames
to add some extra buffer size to meet the constraint.
The change is mainly on the soundwire tree. It would be better to go
through the soundwire tree.

Bard Liao (7):
  soundwire: cadence_master: make frame index trace more readable
  soundwire: only compute BPT stream in sdw_compute_dp0_port_params
  soundwire: cadence_master: set data_per_frame as frame capability
  soundwire: cadence: export sdw_cdns_bpt_find_bandwidth
  ASoC: SOF: Intel: export hda_sdw_bpt_get_buf_size_aligment
  soundwire: cadence_master: add fake_size parameter to
    sdw_cdns_prepare_read_dma_buffer
  soundwire: intel_ace2x: add fake frame to BRA read command

 drivers/soundwire/cadence_master.c            | 85 +++++++++++++++++--
 drivers/soundwire/cadence_master.h            |  7 +-
 .../soundwire/generic_bandwidth_allocation.c  |  3 +
 drivers/soundwire/intel_ace2x.c               | 61 +++++++++++--
 include/sound/hda-sdw-bpt.h                   |  7 ++
 sound/soc/sof/intel/hda-sdw-bpt.c             | 13 +++
 6 files changed, 161 insertions(+), 15 deletions(-)

-- 
2.43.0

[PATCH 1/7] soundwire: cadence_master: make frame index trace more readable

[Bard Liao]

The existing code uses i as the frame index which is 0 based. And
"bad frame %d/%d", i, num_frames where num_frames is 1 based. Change the
frame index to i + 1 to align with num_frames and more readable.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
---
 drivers/soundwire/cadence_master.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 21bb491d026b..c59a98b408b3 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -2495,14 +2495,14 @@ int sdw_cdns_check_write_response(struct device *dev, u8 *dma_buffer,
 		ret = check_frame_start(header, counter);
 		if (ret < 0) {
 			dev_err(dev, "%s: bad frame %d/%d start header %x\n",
-				__func__, i, num_frames, header);
+				__func__, i + 1, num_frames, header);
 			return ret;
 		}
 
 		ret = check_frame_end(footer);
 		if (ret < 0) {
 			dev_err(dev, "%s: bad frame %d/%d end footer %x\n",
-				__func__, i, num_frames, footer);
+				__func__, i + 1, num_frames, footer);
 			return ret;
 		}
 
@@ -2573,7 +2573,7 @@ int sdw_cdns_check_read_response(struct device *dev, u8 *dma_buffer, int dma_buf
 		ret = check_frame_start(header, counter);
 		if (ret < 0) {
 			dev_err(dev, "%s: bad frame %d/%d start header %x\n",
-				__func__, i, num_frames, header);
+				__func__, i + 1, num_frames, header);
 			return ret;
 		}
 
@@ -2588,7 +2588,7 @@ int sdw_cdns_check_read_response(struct device *dev, u8 *dma_buffer, int dma_buf
 
 		if (crc != expected_crc) {
 			dev_err(dev, "%s: bad frame %d/%d crc %#x expected %#x\n",
-				__func__, i, num_frames, crc, expected_crc);
+				__func__, i + 1, num_frames, crc, expected_crc);
 			return -EIO;
 		}
 
@@ -2599,7 +2599,7 @@ int sdw_cdns_check_read_response(struct device *dev, u8 *dma_buffer, int dma_buf
 		ret = check_frame_end(footer);
 		if (ret < 0) {
 			dev_err(dev, "%s: bad frame %d/%d end footer %x\n",
-				__func__, i, num_frames, footer);
+				__func__, i + 1, num_frames, footer);
 			return ret;
 		}
 
-- 
2.43.0

[PATCH 2/7] soundwire: only compute BPT stream in sdw_compute_dp0_port_params

[Bard Liao]

DP0 is only for BPT stream. We should not compute and update the port
params of the normal audio streams.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
---
 drivers/soundwire/generic_bandwidth_allocation.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/soundwire/generic_bandwidth_allocation.c b/drivers/soundwire/generic_bandwidth_allocation.c
index c18f0c16f929..530ac66ac6fa 100644
--- a/drivers/soundwire/generic_bandwidth_allocation.c
+++ b/drivers/soundwire/generic_bandwidth_allocation.c
@@ -124,6 +124,9 @@ static void sdw_compute_dp0_port_params(struct sdw_bus *bus)
 	struct sdw_master_runtime *m_rt;
 
 	list_for_each_entry(m_rt, &bus->m_rt_list, bus_node) {
+		/* DP0 is for BPT only */
+		if (m_rt->stream->type != SDW_STREAM_BPT)
+			continue;
 		sdw_compute_dp0_master_ports(m_rt);
 		sdw_compute_dp0_slave_ports(m_rt);
 	}
-- 
2.43.0

[PATCH 3/7] soundwire: cadence_master: set data_per_frame as frame capability

[Bard Liao]

data_per_frame will be used for preparing the TX buffer and we may add
some fake frames to ensure the data in the buffer will be flushed.
So that it should indicate the frame capability even if the required
data bytes are less than the frame capability.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
---
 drivers/soundwire/cadence_master.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index c59a98b408b3..178341410909 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -2114,9 +2114,6 @@ int sdw_cdns_bpt_find_buffer_sizes(int command, /* 0: write, 1: read */
 	if (!actual_bpt_bytes)
 		return -EINVAL;
 
-	if (data_bytes < actual_bpt_bytes)
-		actual_bpt_bytes = data_bytes;
-
 	/*
 	 * the caller may want to set the number of bytes per frame,
 	 * allow when possible
@@ -2126,6 +2123,9 @@ int sdw_cdns_bpt_find_buffer_sizes(int command, /* 0: write, 1: read */
 
 	*data_per_frame = actual_bpt_bytes;
 
+	if (data_bytes < actual_bpt_bytes)
+		actual_bpt_bytes = data_bytes;
+
 	if (command == 0) {
 		/*
 		 * for writes we need to send all the data_bytes per frame,
-- 
2.43.0

[PATCH 4/7] soundwire: cadence: export sdw_cdns_bpt_find_bandwidth

[Bard Liao]

Currently, we calculate the required bandwidth after the PDI buffer size
is calculated. However as we need to add some fake frame to align the
data block size, the final PDI size and the frame number will change.
Besides, we need the required bandwidth to decide the DMA channel number
and the channel number will be used to calculate the data block size.
Therefore, we calculate the required bandwidth and export a helper for
the caller to get the required bandwidth.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
---
 drivers/soundwire/cadence_master.c | 30 ++++++++++++++++++++++++++++++
 drivers/soundwire/cadence_master.h |  5 +++++
 2 files changed, 35 insertions(+)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 178341410909..57671f9b3e9c 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -2094,6 +2094,36 @@ static unsigned int sdw_cdns_read_pdi1_buffer_size(unsigned int actual_data_size
 	return total * 2;
 }
 
+int sdw_cdns_bpt_find_bandwidth(int command, /* 0: write, 1: read */
+				int row, int col, int frame_rate,
+				unsigned int *tx_dma_bandwidth,
+				unsigned int *rx_dma_bandwidth)
+{
+	unsigned int bpt_bits = row * (col - 1);
+	unsigned int bpt_bytes = bpt_bits >> 3;
+	unsigned int pdi0_buffer_size;
+	unsigned int pdi1_buffer_size;
+	unsigned int data_per_frame;
+
+	data_per_frame = sdw_cdns_bra_actual_data_size(bpt_bytes);
+	if (!data_per_frame)
+		return -EINVAL;
+
+	if (command == 0) {
+		pdi0_buffer_size = sdw_cdns_write_pdi0_buffer_size(data_per_frame);
+		pdi1_buffer_size = SDW_CDNS_WRITE_PDI1_BUFFER_SIZE;
+	} else {
+		pdi0_buffer_size = SDW_CDNS_READ_PDI0_BUFFER_SIZE;
+		pdi1_buffer_size = sdw_cdns_read_pdi1_buffer_size(data_per_frame);
+	}
+
+	*tx_dma_bandwidth = pdi0_buffer_size * 8 * frame_rate;
+	*rx_dma_bandwidth = pdi1_buffer_size * 8 * frame_rate;
+
+	return 0;
+}
+EXPORT_SYMBOL(sdw_cdns_bpt_find_bandwidth);
+
 int sdw_cdns_bpt_find_buffer_sizes(int command, /* 0: write, 1: read */
 				   int row, int col, unsigned int data_bytes,
 				   unsigned int requested_bytes_per_frame,
diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h
index 9373426c7f63..6830d7f2d772 100644
--- a/drivers/soundwire/cadence_master.h
+++ b/drivers/soundwire/cadence_master.h
@@ -209,6 +209,11 @@ void sdw_cdns_config_update(struct sdw_cdns *cdns);
 int sdw_cdns_config_update_set_wait(struct sdw_cdns *cdns);
 
 /* SoundWire BPT/BRA helpers to format data */
+int sdw_cdns_bpt_find_bandwidth(int command, /* 0: write, 1: read */
+				int row, int col, int frame_rate,
+				unsigned int *tx_dma_bandwidth,
+				unsigned int *rx_dma_bandwidth);
+
 int sdw_cdns_bpt_find_buffer_sizes(int command, /* 0: write, 1: read */
 				   int row, int col, unsigned int data_bytes,
 				   unsigned int requested_bytes_per_frame,
-- 
2.43.0

[PATCH 5/7] ASoC: SOF: Intel: export hda_sdw_bpt_get_buf_size_aligment

[Bard Liao]

The dma buffer need to be a multiple of data block size and
the fifo size. Export a function to return the LCM of data
block size and the fifo size.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
---
 include/sound/hda-sdw-bpt.h       |  7 +++++++
 sound/soc/sof/intel/hda-sdw-bpt.c | 13 +++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/include/sound/hda-sdw-bpt.h b/include/sound/hda-sdw-bpt.h
index f649549b75d5..9b654c31829a 100644
--- a/include/sound/hda-sdw-bpt.h
+++ b/include/sound/hda-sdw-bpt.h
@@ -30,6 +30,8 @@ int hda_sdw_bpt_wait(struct device *dev, struct hdac_ext_stream *bpt_tx_stream,
 int hda_sdw_bpt_close(struct device *dev, struct hdac_ext_stream *bpt_tx_stream,
 		      struct snd_dma_buffer *dmab_tx_bdl, struct hdac_ext_stream *bpt_rx_stream,
 		      struct snd_dma_buffer *dmab_rx_bdl);
+
+unsigned int hda_sdw_bpt_get_buf_size_alignment(unsigned int dma_bandwidth);
 #else
 static inline int hda_sdw_bpt_open(struct device *dev, int link_id,
 				   struct hdac_ext_stream **bpt_tx_stream,
@@ -64,6 +66,11 @@ static inline int hda_sdw_bpt_close(struct device *dev, struct hdac_ext_stream *
 	WARN_ONCE(1, "SoundWire BPT is disabled");
 	return -EOPNOTSUPP;
 }
+
+static inline unsigned int hda_sdw_bpt_get_buf_size_alignment(unsigned int dma_bandwidth)
+{
+	return 0;
+}
 #endif
 
 #endif /* __HDA_SDW_BPT_H */
diff --git a/sound/soc/sof/intel/hda-sdw-bpt.c b/sound/soc/sof/intel/hda-sdw-bpt.c
index 1327f1cad0bc..11df4cf1e33e 100644
--- a/sound/soc/sof/intel/hda-sdw-bpt.c
+++ b/sound/soc/sof/intel/hda-sdw-bpt.c
@@ -10,6 +10,7 @@
  * Hardware interface for SoundWire BPT support with HDA DMA
  */
 
+#include <linux/lcm.h>
 #include <sound/hdaudio_ext.h>
 #include <sound/hda-mlink.h>
 #include <sound/hda-sdw-bpt.h>
@@ -236,6 +237,18 @@ static int hda_sdw_bpt_dma_disable(struct device *dev, struct hdac_ext_stream *s
 	return ret;
 }
 
+#define FIFO_ALIGNMENT	64
+
+unsigned int hda_sdw_bpt_get_buf_size_alignment(unsigned int dma_bandwidth)
+{
+	unsigned int num_channels = DIV_ROUND_UP(dma_bandwidth, BPT_FREQUENCY * 32);
+	unsigned int data_block = num_channels * 4;
+	unsigned int alignment = lcm(data_block, FIFO_ALIGNMENT);
+
+	return alignment;
+}
+EXPORT_SYMBOL_NS(hda_sdw_bpt_get_buf_size_alignment, "SND_SOC_SOF_INTEL_HDA_SDW_BPT");
+
 int hda_sdw_bpt_open(struct device *dev, int link_id, struct hdac_ext_stream **bpt_tx_stream,
 		     struct snd_dma_buffer *dmab_tx_bdl, u32 bpt_tx_num_bytes,
 		     u32 tx_dma_bandwidth, struct hdac_ext_stream **bpt_rx_stream,
-- 
2.43.0

[PATCH 6/7] soundwire: cadence_master: add fake_size parameter to sdw_cdns_prepare_read_dma_buffer

[Bard Liao]

We may need to add few fake frames to fit the aligned read dma buffer
size. Add a fake_size parameter to allow the caller to set the fake data
size.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
---
 drivers/soundwire/cadence_master.c | 39 +++++++++++++++++++++++++++++-
 drivers/soundwire/cadence_master.h |  2 +-
 drivers/soundwire/intel_ace2x.c    |  2 +-
 3 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 57671f9b3e9c..4e94da28d8ad 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -2393,7 +2393,7 @@ EXPORT_SYMBOL(sdw_cdns_prepare_write_dma_buffer);
 
 int sdw_cdns_prepare_read_dma_buffer(u8 dev_num, u32 start_register, int data_size,
 				     int data_per_frame, u8 *dma_buffer, int dma_buffer_size,
-				     int *dma_buffer_total_bytes)
+				     int *dma_buffer_total_bytes, unsigned int fake_size)
 {
 	int total_dma_data_written = 0;
 	u8 *p_dma_buffer = dma_buffer;
@@ -2445,6 +2445,43 @@ int sdw_cdns_prepare_read_dma_buffer(u8 dev_num, u32 start_register, int data_si
 		if (ret < 0)
 			return ret;
 
+		counter++;
+
+		p_dma_buffer += dma_data_written;
+		dma_buffer_size -= dma_data_written;
+		total_dma_data_written += dma_data_written;
+	}
+
+	/* Add fake frame */
+	header[0] &= ~GENMASK(7, 6);	/* Set inactive flag in BPT/BRA frame heade */
+	while (fake_size >= data_per_frame) {
+		header[1] = data_per_frame;
+		ret = sdw_cdns_prepare_read_pd0_buffer(header, SDW_CDNS_BRA_HDR, p_dma_buffer,
+						       dma_buffer_size, &dma_data_written,
+						       counter);
+		if (ret < 0)
+			return ret;
+
+		counter++;
+
+		fake_size -= data_per_frame;
+		p_dma_buffer += dma_data_written;
+		dma_buffer_size -= dma_data_written;
+		total_dma_data_written += dma_data_written;
+	}
+
+	if (fake_size) {
+		header[1] = fake_size;
+		ret = sdw_cdns_prepare_read_pd0_buffer(header, SDW_CDNS_BRA_HDR, p_dma_buffer,
+						       dma_buffer_size, &dma_data_written,
+						       counter);
+		if (ret < 0)
+			return ret;
+
+		counter++;
+
+		p_dma_buffer += dma_data_written;
+		dma_buffer_size -= dma_data_written;
 		total_dma_data_written += dma_data_written;
 	}
 
diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h
index 6830d7f2d772..a269a87486fc 100644
--- a/drivers/soundwire/cadence_master.h
+++ b/drivers/soundwire/cadence_master.h
@@ -226,7 +226,7 @@ int sdw_cdns_prepare_write_dma_buffer(u8 dev_num, u32 start_register, u8 *data,
 
 int sdw_cdns_prepare_read_dma_buffer(u8 dev_num, u32 start_register, int data_size,
 				     int data_per_frame, u8 *dma_buffer, int dma_buffer_size,
-				     int *dma_buffer_total_bytes);
+				     int *dma_buffer_total_bytes, unsigned int fake_size);
 
 int sdw_cdns_check_write_response(struct device *dev, u8 *dma_buffer,
 				  int dma_buffer_size, int num_frames);
diff --git a/drivers/soundwire/intel_ace2x.c b/drivers/soundwire/intel_ace2x.c
index 5d08364ad6d1..22118b053d56 100644
--- a/drivers/soundwire/intel_ace2x.c
+++ b/drivers/soundwire/intel_ace2x.c
@@ -177,7 +177,7 @@ static int intel_ace2x_bpt_open_stream(struct sdw_intel *sdw, struct sdw_slave *
 		ret = sdw_cdns_prepare_read_dma_buffer(msg->dev_num, msg->addr,	msg->len,
 						       data_per_frame,
 						       sdw->bpt_ctx.dmab_tx_bdl.area,
-						       pdi0_buffer_size, &tx_total_bytes);
+						       pdi0_buffer_size, &tx_total_bytes, 0);
 	}
 
 	if (!ret)
-- 
2.43.0

[PATCH 7/7] soundwire: intel_ace2x: add fake frame to BRA read command

[Bard Liao]

Intel DMA buffer size need to be a multiple of data block size.
Find the minimal fake data size and extra buffer size to meet the
requirement.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
---
 drivers/soundwire/intel_ace2x.c | 61 ++++++++++++++++++++++++++++++---
 1 file changed, 56 insertions(+), 5 deletions(-)

diff --git a/drivers/soundwire/intel_ace2x.c b/drivers/soundwire/intel_ace2x.c
index 22118b053d56..e11a0cf77193 100644
--- a/drivers/soundwire/intel_ace2x.c
+++ b/drivers/soundwire/intel_ace2x.c
@@ -44,6 +44,8 @@ static int sdw_slave_bpt_stream_add(struct sdw_slave *slave, struct sdw_stream_r
 	return ret;
 }
 
+#define READ_PDI1_MIN_SIZE	12
+
 static int intel_ace2x_bpt_open_stream(struct sdw_intel *sdw, struct sdw_slave *slave,
 				       struct sdw_bpt_msg *msg)
 {
@@ -53,15 +55,23 @@ static int intel_ace2x_bpt_open_stream(struct sdw_intel *sdw, struct sdw_slave *
 	struct sdw_stream_runtime *stream;
 	struct sdw_stream_config sconfig;
 	struct sdw_port_config *pconfig;
+	unsigned int pdi0_buf_size_pre_frame;
+	unsigned int pdi1_buf_size_pre_frame;
 	unsigned int pdi0_buffer_size;
 	unsigned int tx_dma_bandwidth;
 	unsigned int pdi1_buffer_size;
 	unsigned int rx_dma_bandwidth;
+	unsigned int fake_num_frames;
 	unsigned int data_per_frame;
 	unsigned int tx_total_bytes;
 	struct sdw_cdns_pdi *pdi0;
 	struct sdw_cdns_pdi *pdi1;
+	unsigned int rx_alignment;
+	unsigned int tx_alignment;
 	unsigned int num_frames;
+	unsigned int fake_size;
+	unsigned int tx_pad;
+	unsigned int rx_pad;
 	int command;
 	int ret1;
 	int ret;
@@ -138,6 +148,13 @@ static int intel_ace2x_bpt_open_stream(struct sdw_intel *sdw, struct sdw_slave *
 
 	command = (msg->flags & SDW_MSG_FLAG_WRITE) ? 0 : 1;
 
+	ret = sdw_cdns_bpt_find_bandwidth(command, cdns->bus.params.row,
+					  cdns->bus.params.col,
+					  prop->default_frame_rate,
+					  &tx_dma_bandwidth, &rx_dma_bandwidth);
+	if (ret < 0)
+		goto deprepare_stream;
+
 	ret = sdw_cdns_bpt_find_buffer_sizes(command, cdns->bus.params.row, cdns->bus.params.col,
 					     msg->len, SDW_BPT_MSG_MAX_BYTES, &data_per_frame,
 					     &pdi0_buffer_size, &pdi1_buffer_size, &num_frames);
@@ -148,10 +165,43 @@ static int intel_ace2x_bpt_open_stream(struct sdw_intel *sdw, struct sdw_slave *
 	sdw->bpt_ctx.pdi1_buffer_size = pdi1_buffer_size;
 	sdw->bpt_ctx.num_frames = num_frames;
 	sdw->bpt_ctx.data_per_frame = data_per_frame;
-	tx_dma_bandwidth = div_u64((u64)pdi0_buffer_size * 8 * (u64)prop->default_frame_rate,
-				   num_frames);
-	rx_dma_bandwidth = div_u64((u64)pdi1_buffer_size * 8 * (u64)prop->default_frame_rate,
-				   num_frames);
+
+	rx_alignment = hda_sdw_bpt_get_buf_size_alignment(rx_dma_bandwidth);
+	tx_alignment = hda_sdw_bpt_get_buf_size_alignment(tx_dma_bandwidth);
+
+	if (command) { /* read */
+		/* Get buffer size of a full frame */
+		ret = sdw_cdns_bpt_find_buffer_sizes(command, cdns->bus.params.row,
+						     cdns->bus.params.col,
+						     data_per_frame, SDW_BPT_MSG_MAX_BYTES,
+						     &data_per_frame, &pdi0_buf_size_pre_frame,
+						     &pdi1_buf_size_pre_frame, &fake_num_frames);
+		if (ret < 0)
+			goto deprepare_stream;
+
+		/* find fake pdi1 buffer size */
+		rx_pad = rx_alignment - (pdi1_buffer_size % rx_alignment);
+		while (rx_pad <= READ_PDI1_MIN_SIZE)
+			rx_pad += rx_alignment;
+
+		pdi1_buffer_size += rx_pad;
+		/* It is fine if we request more than enough byte to read */
+		fake_num_frames = DIV_ROUND_UP(rx_pad, pdi1_buf_size_pre_frame);
+		fake_size = fake_num_frames * data_per_frame;
+
+		/* find fake pdi0 buffer size */
+		pdi0_buffer_size += (fake_num_frames * pdi0_buf_size_pre_frame);
+		tx_pad = tx_alignment - (pdi0_buffer_size % tx_alignment);
+		pdi0_buffer_size += tx_pad;
+	} else { /* write */
+		/*
+		 * For the write command, the rx data block is 4, and the rx buffer size of a frame
+		 * is 8. So the rx buffer size (pdi0_buffer_size) is always a multiple of rx
+		 * alignment.
+		 */
+		tx_pad = tx_alignment - (pdi0_buffer_size % tx_alignment);
+		pdi0_buffer_size += tx_pad;
+	}
 
 	dev_dbg(cdns->dev, "Message len %d transferred in %d frames (%d per frame)\n",
 		msg->len, num_frames, data_per_frame);
@@ -177,7 +227,8 @@ static int intel_ace2x_bpt_open_stream(struct sdw_intel *sdw, struct sdw_slave *
 		ret = sdw_cdns_prepare_read_dma_buffer(msg->dev_num, msg->addr,	msg->len,
 						       data_per_frame,
 						       sdw->bpt_ctx.dmab_tx_bdl.area,
-						       pdi0_buffer_size, &tx_total_bytes, 0);
+						       pdi0_buffer_size, &tx_total_bytes,
+						       fake_size);
 	}
 
 	if (!ret)
-- 
2.43.0

Re: [PATCH 0/7] ASoC/soundwire: add fake BPT frame to align Intel DMA buffer size

[Vinod Koul]

On Tue, 14 Oct 2025 11:14:43 +0800, Bard Liao wrote:
> There is a constraint on Intel DMA buffer size that needs to be a
> multiple of data block size. This series adds some fake BRA frames
> to add some extra buffer size to meet the constraint.
> The change is mainly on the soundwire tree. It would be better to go
> through the soundwire tree.
> 
> Bard Liao (7):
>   soundwire: cadence_master: make frame index trace more readable
>   soundwire: only compute BPT stream in sdw_compute_dp0_port_params
>   soundwire: cadence_master: set data_per_frame as frame capability
>   soundwire: cadence: export sdw_cdns_bpt_find_bandwidth
>   ASoC: SOF: Intel: export hda_sdw_bpt_get_buf_size_aligment
>   soundwire: cadence_master: add fake_size parameter to
>     sdw_cdns_prepare_read_dma_buffer
>   soundwire: intel_ace2x: add fake frame to BRA read command
> 
> [...]

Applied, thanks!

[1/7] soundwire: cadence_master: make frame index trace more readable
      commit: 464101450bf8c16be6f6bd2cc48d3dfd7ab4a23a
[2/7] soundwire: only compute BPT stream in sdw_compute_dp0_port_params
      commit: 101bfbe88ae4944263fd58b2e0c265db263f793a
[3/7] soundwire: cadence_master: set data_per_frame as frame capability
      commit: 558abe5fadd03579351ce1c752b5961984b0fb86
[4/7] soundwire: cadence: export sdw_cdns_bpt_find_bandwidth
      commit: 207a5831b34834dd97ed2f0100bf936cf67e54c3
[5/7] ASoC: SOF: Intel: export hda_sdw_bpt_get_buf_size_aligment
      commit: 10ed028f7851f41d391c6b6516c9f8b3f95fac8f
[6/7] soundwire: cadence_master: add fake_size parameter to sdw_cdns_prepare_read_dma_buffer
      commit: d7941dc674aed1e9eed5e17fe46c3dde884fc948
[7/7] soundwire: intel_ace2x: add fake frame to BRA read command
      commit: 420399049ebba154bb82d5024d9a7d2de19ce1f8

Best regards,
-- 
~Vinod