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ols: Fix RLE count handling 

The high bit of the sample, denoting this is a count, was not getting
properly cleared. This resulted in an inevitably negative count, and
corruption of the sample buffer before it was transferred to the
frontend.
This commit is contained in:
Bert Vermeulen 2013-08-27 00:33:20 +02:00
parent abb39e6b8c
commit 00d04d3b0e
2 changed files with 11 additions and 11 deletions
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20
hardware/openbench-logic-sniffer/protocol.c
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@ -340,7 +340,8 @@ SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
struct sr_dev_inst *sdi;
GSList *l;
uint32_t sample;
int num_channels, offset, i, j;
int num_channels, offset, j;
unsigned int i;
unsigned char byte;
drvc = di->priv;
@ -394,23 +395,22 @@ SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
devc->sample[devc->num_bytes++] = byte;
sr_dbg("Received byte 0x%.2x.", byte);
if (devc->num_bytes == num_channels) {
/* Got a full sample. */
/* Got a full sample. Convert from the OLS's little-endian
* sample to the local format. */
sample = devc->sample[0] | (devc->sample[1] << 8) \
| (devc->sample[2] << 16) | (devc->sample[3] << 24);
sr_dbg("Received sample 0x%.*x.", devc->num_bytes * 2, sample);
if (devc->flag_reg & FLAG_RLE) {
/*
* In RLE mode -1 should never come in as a
* sample, because bit 31 is the "count" flag.
* In RLE mode the high bit of the sample is the
* "count" flag, meaning this sample is the number
* of times the previous sample occurred.
*/
if (devc->sample[devc->num_bytes - 1] & 0x80) {
devc->sample[devc->num_bytes - 1] &= 0x7f;
/*
* FIXME: This will only work on
* little-endian systems.
*/
/* Clear the high bit. */
sample &= ~(0x80 << (devc->num_bytes - 1) * 8);
devc->rle_count = sample;
sr_dbg("RLE count: %d.", devc->rle_count);
sr_dbg("RLE count: %u.", devc->rle_count);
devc->num_bytes = 0;
return TRUE;
}

2
hardware/openbench-logic-sniffer/protocol.h
View File

@ -103,7 +103,7 @@ struct dev_context {
int num_bytes;
/* Temporary variables */
int rle_count;
unsigned int rle_count;
unsigned char sample[4];
unsigned char tmp_sample[4];
unsigned char *raw_sample_buf;