soundwire: intel_ace2x: add fake frame to BRA read command

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>
Link: https://patch.msgid.link/20251030070253.1216871-8-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/soundwire/intel_ace2x.c b/drivers/soundwire/intel_ace2x.c
index 22118b053d56ab2063ebfd0150692d47c3d7ac1e..e11a0cf771936a7aaca97fbd85e3c1c7a4b1affa 100644 (file)
--- 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)