soundwire: update Intel BPT message length limitation

The limitation of "must be multiples of 32 bytes" does not fit the
requirement of current Intel platforms. Update it to meet the
requirement.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20250429122337.142551-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/Documentation/driver-api/soundwire/bra.rst b/Documentation/driver-api/soundwire/bra.rst
index 8500253fa3e8ca67367dde5a6196c816affacf43..c08ab2591496d3654207095745f8ddd4a84fdb58 100644 (file)
--- a/Documentation/driver-api/soundwire/bra.rst
+++ b/Documentation/driver-api/soundwire/bra.rst
@@ -333,4 +333,4 @@ FIFO sizes to avoid xruns.
 
 Alignment requirements are currently not enforced at the core level
 but at the platform-level, e.g. for Intel the data sizes must be
-multiples of 32 bytes.
+equal to or larger than 16 bytes.

diff --git a/drivers/soundwire/intel_ace2x.c b/drivers/soundwire/intel_ace2x.c
index 7e893e4f48d6e52e4685862c916e4a89e9a53373..5d08364ad6d141e90382b09f561ba58d713577c6 100644 (file)
--- a/drivers/soundwire/intel_ace2x.c
+++ b/drivers/soundwire/intel_ace2x.c
@@ -246,7 +246,7 @@ static void intel_ace2x_bpt_close_stream(struct sdw_intel *sdw, struct sdw_slave
        cdns->bus.bpt_stream = NULL;
 }
 
-#define INTEL_BPT_MSG_BYTE_ALIGNMENT 32
+#define INTEL_BPT_MSG_BYTE_MIN 16
 
 static int intel_ace2x_bpt_send_async(struct sdw_intel *sdw, struct sdw_slave *slave,
                                      struct sdw_bpt_msg *msg)
@@ -254,9 +254,9 @@ static int intel_ace2x_bpt_send_async(struct sdw_intel *sdw, struct sdw_slave *s
        struct sdw_cdns *cdns = &sdw->cdns;
        int ret;
 
-       if (msg->len % INTEL_BPT_MSG_BYTE_ALIGNMENT) {
-               dev_err(cdns->dev, "BPT message length %d is not a multiple of %d bytes\n",
-                       msg->len, INTEL_BPT_MSG_BYTE_ALIGNMENT);
+       if (msg->len < INTEL_BPT_MSG_BYTE_MIN) {
+               dev_err(cdns->dev, "BPT message length %d is less than the minimum bytes %d\n",
+                       msg->len, INTEL_BPT_MSG_BYTE_MIN);
                return -EINVAL;
        }