sm_io/*/acq/*: fix (again) number of pre/post acquisition samples

We need to acquire a multiple number of samples_alignment value. With samples_alignment being 4 (typical for the ADC and ADCSWAP channels), the following equation yields correct results: num_samples_aligned = num_samples_pre + num_samples_aligned - (num_samples_pre % num_samples_aligned)

sm_io//acq/: fix (again) number of pre/post acquisition samples
We need to acquire a multiple number of samples_alignment value. With samples_alignment being 4 (typical for the ADC and ADCSWAP channels), the following equation yields correct results: num_samples_aligned = num_samples_pre + num_samples_aligned - (num_samples_pre % num_samples_aligned)
8db32b93 · Lucas Russo · c7885ba4 · 8db32b93
Commit 8db32b93 authored Nov 09, 2015 by Lucas Russo
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sm_io_acq_exp.c src/sm_io/modules/acq/sm_io_acq_exp.c +4 -2

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--- a/src/sm_io/modules/acq/sm_io_acq_exp.c
+++ b/src/sm_io/modules/acq/sm_io_acq_exp.c
@@ -161,8 +161,10 @@ static int _acq_data_acquire (void *owner, void *args, void *ret)
     * acquisition channel sample size */
    uint32_t samples_alignment =
        DDR3_PAYLOAD_SIZE/acq->acq_buf[chan].sample_size;
-    uint32_t num_samples_pre_aligned = num_samples_pre + (num_samples_pre % samples_alignment);
-    uint32_t num_samples_post_aligned = num_samples_post + (num_samples_post % samples_alignment);
+    uint32_t num_samples_pre_aligned = num_samples_pre + samples_alignment -
+        (num_samples_pre % samples_alignment);
+    uint32_t num_samples_post_aligned = num_samples_post + samples_alignment -
+        (num_samples_post % samples_alignment);

    /* Set the parameters: number of samples of this channel */
    acq->acq_params[chan].num_samples_pre = num_samples_pre_aligned;