probe: logging: Return the bytes written in probe_logging_hook()

Write only the amount of bytes that fits to DMA buffer and return the
amount written.

Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

Author: Jyri Sarha

src/include/sof/probe/probe.h

@@ -13,7 +13,7 @@
 /**
  * A buffer of logging data is available for processing.
  */
-typedef void(*probe_logging_hook_t)(uint8_t *buffer, size_t length);
+typedef int(*probe_logging_hook_t)(uint8_t *buffer, size_t length);
 
 #if CONFIG_LOG_BACKEND_SOF_PROBE
 const struct log_backend *log_backend_probe_get(void);

src/probe/probe.c

@@ -865,27 +865,32 @@ static void kick_probe_task(struct probe_pdata *_probe)
 }
 
 #if CONFIG_LOG_BACKEND_SOF_PROBE
-static void probe_logging_hook(uint8_t *buffer, size_t length)
+static int probe_logging_hook(uint8_t *buffer, size_t length)
 {
 	struct probe_pdata *_probe = probe_get();
+	uint32_t max_len;
 	uint64_t checksum;
 	int ret;
 
+	max_len = _probe->ext_dma.dmapb.avail - sizeof(struct probe_data_packet) - sizeof(checksum);
+	length = MIN(max_len, (uint32_t)length);
+
 	ret = probe_gen_header(PROBE_LOGGING_BUFFER_ID, length, 0, &checksum);
 	if (ret < 0)
-		return;
+		return ret;
 
 	ret = copy_to_pbuffer(&_probe->ext_dma.dmapb,
 			      buffer, length);
 	if (ret < 0)
-		return;
+		return ret;
 
 	ret = copy_to_pbuffer(&_probe->ext_dma.dmapb,
 			      &checksum, sizeof(checksum));
 	if (ret < 0)
-		return;
+		return ret;
 
 	kick_probe_task(_probe);
+	return length;
 }
 #endif