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rlink: simplify and optimize queue fill level checks

Add a helper function for running the queue if it would overflow otherwise.
Use it to simplify the queue fill level checks and optimize in a few cases
that would previously run the queue prematurely.

Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
tags/v0.6.0-rc1
Andreas Fritiofson 12 years ago
committed by Øyvind Harboe
parent
commit
0b64be2019
1 changed files with 34 additions and 44 deletions
  1. +34
    -44
      src/jtag/drivers/rlink.c

+ 34
- 44
src/jtag/drivers/rlink.c View File

@@ -799,6 +799,24 @@ dtc_queue_run(void) {
return(retval);
}

/* runs the queue if it cannot take reserved_cmd bytes of command data
* or reserved_reply bytes of reply data */
static
int
dtc_queue_run_if_full(
int reserved_cmd,
int reserved_reply
) {
/* reserve one additional byte for the STOP cmd appended during run */
if (dtc_queue.cmd_index + reserved_cmd + 1 > USB_EP2BANK_SIZE)
return dtc_queue_run();

if (dtc_queue.reply_index + reserved_reply > USB_EP2IN_SIZE)
return dtc_queue_run();

return ERROR_OK;
}

static
int
tap_state_queue_init(void) {
@@ -829,12 +847,8 @@ tap_state_queue_run(void) {
if ((bits >= 8) || !i) {
byte_param <<= (8 - bits);

/* make sure there's room for stop, byte op, and one byte */
if (dtc_queue.cmd_index >= (sizeof(dtc_queue.cmd_buffer) - (1 + 1 + 1))) {
dtc_queue.cmd_buffer[dtc_queue.cmd_index++] =
DTC_CMD_STOP;
dtc_queue_run();
}
/* make sure there's room for two cmd bytes */
dtc_queue_run_if_full(2, 0);

#ifdef USE_HARDWARE_SHIFTER_FOR_TMS
if (bits == 8) {
@@ -1145,12 +1159,9 @@ rlink_scan(
if (extra_bits && (type == SCAN_OUT)) {
/* Schedule any extra bits into the DTC command buffer, padding as needed */
/* For SCAN_OUT, this comes before the full bytes so the (leading) padding bits will fall off the end */
/* make sure there's room for stop, byte op, and one byte */
if (
(dtc_queue.cmd_index >= sizeof(dtc_queue.cmd_buffer) - (1 + 1 + 1))
) {
dtc_queue_run();
}

/* make sure there's room for two cmd bytes */
dtc_queue_run_if_full(2, 0);

x = 0;
dtc_mask = 1 << (extra_bits - 1);
@@ -1177,22 +1188,9 @@ rlink_scan(

/* Loop scheduling full bytes into the DTC command buffer */
while (byte_bits) {
if (type == SCAN_IN) {
/* make sure there's room for stop and byte op */
x = (dtc_queue.cmd_index >= sizeof(dtc_queue.cmd_buffer) - (1 + 1));
} else {
/* make sure there's room for stop, byte op, and at least one byte */
x = (dtc_queue.cmd_index >= sizeof(dtc_queue.cmd_buffer) - (1 + 1 + 1));
}

if (type != SCAN_OUT) {
/* make sure there's room for at least one reply byte */
x |= (dtc_queue.reply_index >= USB_EP2IN_SIZE - (1));
}

if (x) {
dtc_queue_run();
}
/* make sure there's room for one (for in scans) or two cmd bytes and
* at least one reply byte for in or inout scans*/
dtc_queue_run_if_full(type == SCAN_IN ? 1 : 2, type != SCAN_OUT ? 1 : 0);

chunk_bits = byte_bits;
/* we can only use up to 16 bytes at a time */
@@ -1270,14 +1268,10 @@ rlink_scan(

if (extra_bits && (type != SCAN_OUT)) {
/* Schedule any extra bits into the DTC command buffer */
/* make sure there's room for stop, byte op, and one byte */
if (
(dtc_queue.cmd_index >= sizeof(dtc_queue.cmd_buffer) - (1 + 1 + 1))
||
(dtc_queue.reply_index >= USB_EP2IN_SIZE - (1))
) {
dtc_queue_run();
}

/* make sure there's room for one (for in scans) or two cmd bytes
* and one reply byte */
dtc_queue_run_if_full(type == SCAN_IN ? 1 : 2, 1);

if (dtc_queue_enqueue_reply(
type, buffer, scan_size, tdi_bit_offset,
@@ -1322,14 +1316,10 @@ rlink_scan(
}

/* Schedule the last bit into the DTC command buffer */
/* make sure there's room for stop, and bit pair command */
if (
(dtc_queue.cmd_index >= sizeof(dtc_queue.cmd_buffer) - (1 + 1))
||
(dtc_queue.reply_index >= USB_EP2IN_SIZE - (1))
) {
dtc_queue_run();
}

/* make sure there's room for one cmd byte and one reply byte
* for in or inout scans*/
dtc_queue_run_if_full(1, type == SCAN_OUT ? 0 : 1);

if (type == SCAN_OUT) {
dtc_queue.cmd_buffer[dtc_queue.cmd_index++] =


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