Sigma: Support for decoding partial chunks.

Samples are stored in chunks and the last samples do not fill up
a complete chunk. This patch adds support for decoding partial
chunks.

diff --git a/hardware/asix-sigma/asix-sigma.c b/hardware/asix-sigma/asix-sigma.c
index 7cc7c9da901b97a9d5abf9d2f9561efdd6d3bf8f..abae17a0127ca9552d7ea3715c616a5489f2626d 100644 (file)
--- a/hardware/asix-sigma/asix-sigma.c
+++ b/hardware/asix-sigma/asix-sigma.c
@@ -809,7 +809,8 @@ static int get_trigger_offset(uint16_t *samples, uint16_t last_sample,
  * spread 20 ns apart.
  */
 static int decode_chunk_ts(uint8_t *buf, uint16_t *lastts,
-                          uint16_t *lastsample, int triggerpos, void *user_data)
+                          uint16_t *lastsample, int triggerpos,
+                          uint16_t limit_chunk, void *user_data)
 {
        struct sigrok_device_instance *sdi = user_data;
        struct sigma *sigma = sdi->priv;
@@ -841,6 +842,10 @@ static int decode_chunk_ts(uint8_t *buf, uint16_t *lastts,
                tsdiff = ts - *lastts;
                *lastts = ts;
 
+               /* Decode partial chunk. */
+               if (limit_chunk && ts > limit_chunk)
+                       return SIGROK_OK;
+
                /* Pad last sample up to current point. */
                numpad = tsdiff * sigma->samples_per_event - clustersize;
                if (numpad > 0) {
@@ -991,20 +996,29 @@ static int receive_data(int fd, int revents, void *user_data)
 
                /* Decode chunks and send them to sigrok. */
                for (i = 0; i < newchunks; ++i) {
+                       int limit_chunk = 0;
+
+                       /* The last chunk may potentially be only in part. */
+                       if (sigma->state.chunks_downloaded == numchunks - 1)
+                       {
+                               /* Find the last valid timestamp */
+                               limit_chunk = sigma->state.stoppos % 512 + sigma->state.lastts;
+                       }
+
                        if (sigma->state.chunks_downloaded + i == sigma->state.triggerchunk)
                                decode_chunk_ts(buf + (i * CHUNK_SIZE),
                                                &sigma->state.lastts,
                                                &sigma->state.lastsample,
                                                sigma->state.triggerpos & 0x1ff,
-                                               user_data);
+                                               limit_chunk, user_data);
                        else
                                decode_chunk_ts(buf + (i * CHUNK_SIZE),
                                                &sigma->state.lastts,
                                                &sigma->state.lastsample,
-                                               -1, user_data);
-               }
+                                               -1, limit_chunk, user_data);
 
-               sigma->state.chunks_downloaded += newchunks;
+                       ++sigma->state.chunks_downloaded;
+               }
        }
 
        return TRUE;