tests: Make loopback latency test more accurate

This makes sure that we always take the timing at the point when we
write out the pulse, making the overall latency measurement more
accurate.

diff --git a/src/tests/lo-latency-test.c b/src/tests/lo-latency-test.c
index 124693d..ad5e7a5 100644 (file)
--- a/src/tests/lo-latency-test.c
+++ b/src/tests/lo-latency-test.c
@@ -54,12 +54,17 @@ static void nop_free_cb(void *p) {
 static void write_cb(pa_stream *s, size_t nbytes, void *userdata) {
     pa_lo_test_context *ctx = (pa_lo_test_context *) userdata;
     static int ppos = 0;
-    int r, nsamp = nbytes / ctx->fs;
+    int r, nsamp;
+
+    /* Get the real requested bytes since the last write might have been
+     * incomplete if it caused a wrap around */
+    nbytes = pa_stream_writable_size(s);
+    nsamp = nbytes / ctx->fs;
 
     if (ppos + nsamp > N_OUT) {
-        r = pa_stream_write(s, &out[ppos][0], (N_OUT - ppos) * ctx->fs, nop_free_cb, 0, PA_SEEK_RELATIVE);
-        nbytes -= (N_OUT - ppos) * ctx->fs;
-        ppos = 0;
+        /* Wrap-around, write to end and exit. Next iteration will fill up the
+         * rest */
+        nbytes = (N_OUT - ppos) * ctx->fs;
     }
 
     if (ppos == 0)