[svn-commits] tzafrir: linux/trunk r7625 - /linux/trunk/drivers/dahdi/xpp/
SVN commits to the Digium repositories
svn-commits at lists.digium.com
Sun Nov 22 15:17:18 CST 2009
Author: tzafrir
Date: Sun Nov 22 15:17:16 2009
New Revision: 7625
URL: http://svnview.digium.com/svn/dahdi?view=rev&rev=7625
Log:
xpp: Improved inter-Astribank drift calculation.
Modified:
linux/trunk/drivers/dahdi/xpp/xbus-pcm.c
linux/trunk/drivers/dahdi/xpp/xbus-pcm.h
linux/trunk/drivers/dahdi/xpp/xbus-sysfs.c
Modified: linux/trunk/drivers/dahdi/xpp/xbus-pcm.c
URL: http://svnview.digium.com/svn/dahdi/linux/trunk/drivers/dahdi/xpp/xbus-pcm.c?view=diff&rev=7625&r1=7624&r2=7625
==============================================================================
--- linux/trunk/drivers/dahdi/xpp/xbus-pcm.c (original)
+++ linux/trunk/drivers/dahdi/xpp/xbus-pcm.c Sun Nov 22 15:17:16 2009
@@ -61,8 +61,14 @@
static struct xpp_ticker global_ticks_series;
#define PROC_SYNC "sync"
+#define SYNC_CYCLE 500 /* Sampling cycle in usec */
+#define SYNC_CYCLE_SAMPLE 100 /* Samples from end of SYNC_CYCLE */
+#define SYNC_CONVERGE 10 /* Number of SYNC_CYCLE's to converge speed */
+#define SYNC_CENTER 500 /* Offset from ref_ticker to other AB's */
+#define SYNC_DELTA 40 /* If within +/-SYNC_DELTA, try to stay there */
#define BIG_TICK_INTERVAL 1000
-#define SYNC_ADJ_MAX 63 /* maximal firmware drift unit (63) */
+#define SYNC_ADJ_MAX 20 /* maximal firmware drift unit (hardware limit 63) */
+
/*
* The USB bulk endpoints have a large jitter in the timing of frames
* from the AB to the ehci-hcd. This is because we cannot predict
@@ -123,12 +129,6 @@
return cycled;
}
-static inline void driftinfo_recalc(struct xpp_drift *driftinfo)
-{
- driftinfo->delta_max = INT_MIN;
- driftinfo->delta_min = INT_MAX;
-}
-
/*
* No locking. It is called only from:
* - update_sync_master() in a globall spinlock protected code.
@@ -136,11 +136,12 @@
*/
static inline void xbus_drift_clear(xbus_t *xbus)
{
- struct xpp_drift *driftinfo = &xbus->drift;
-
- driftinfo_recalc(driftinfo);
- driftinfo->calc_drift = 0;
+ struct xpp_drift *di = &xbus->drift;
+
+ do_gettimeofday(&di->last_lost_tick.tv);
ticker_set_cycle(&xbus->ticker, SYNC_ADJ_QUICK);
+ di->max_speed = -SYNC_ADJ_MAX;
+ di->min_speed = SYNC_ADJ_MAX;
}
void xpp_drift_init(xbus_t *xbus)
@@ -148,7 +149,6 @@
memset(&xbus->drift, 0, sizeof(xbus->drift));
spin_lock_init(&xbus->drift.lock);
xpp_ticker_init(&xbus->ticker);
- xbus->drift.wanted_offset = 500;
xbus_drift_clear(xbus);
}
@@ -168,110 +168,123 @@
#define sample_tick(x,y)
#endif
+/*
+ * The following function adjust the clock of an astribank according
+ * to our reference clock (another astribank or another DAHDI device).
+ *
+ * It is VERY hard to stabilise these corrections:
+ * - The measurments are affected by 125usec USB micro-frames.
+ * - However, if we are off by more than +/-500usec we are risking
+ * loosing frames.
+ *
+ * Every change must be tested rigorously with many device combinations
+ * including abrupt changes in sync -- to verify the stability of the
+ * algorithm.
+ */
static void xpp_drift_step(xbus_t *xbus, const struct timeval *tv)
{
- struct xpp_drift *driftinfo = &xbus->drift;
+ struct xpp_drift *di = &xbus->drift;
struct xpp_ticker *ticker = &xbus->ticker;
unsigned long flags;
- bool cycled;
-
- spin_lock_irqsave(&driftinfo->lock, flags);
- cycled = xpp_ticker_step(&xbus->ticker, tv);
+
+ spin_lock_irqsave(&di->lock, flags);
+ xpp_ticker_step(&xbus->ticker, tv);
+ /*
+ * Do we need to be synchronized and is there an established reference
+ * ticker (another Astribank or another DAHDI device) already?
+ */
if(ref_ticker && ref_ticker != &xbus->ticker && syncer && xbus->sync_mode == SYNC_MODE_PLL) {
int new_delta_tick = ticker->count - ref_ticker->count;
- int lost_ticks = new_delta_tick - driftinfo->delta_tick;
-
- driftinfo->delta_tick = new_delta_tick;
+ int lost_ticks = new_delta_tick - di->delta_tick;
+ long usec_delta;
+
+ di->delta_tick = new_delta_tick;
if(lost_ticks) {
static int rate_limit;
- driftinfo->lost_ticks++;
- driftinfo->lost_tick_count += abs(lost_ticks);
-
+ /*
+ * We just lost some ticks. Just report it and don't
+ * try to adjust anything until we are stable again.
+ */
+ di->lost_ticks++;
+ di->lost_tick_count += abs(lost_ticks);
if((rate_limit++ % 1003) == 0) {
- XBUS_DBG(SYNC, xbus, "Lost %d tick%s\n",
+ XBUS_NOTICE(xbus, "Lost %d tick%s\n",
lost_ticks,
(abs(lost_ticks) > 1) ? "s": "");
}
- ticker_set_cycle(ticker, SYNC_ADJ_QUICK);
+ xbus_drift_clear(xbus);
if(abs(lost_ticks) > 100)
ticker->count = ref_ticker->count;
} else {
- long usec_delta;
- bool nofix = 0;
-
+ /* Sample a delta */
usec_delta = (long)usec_diff(
&ticker->last_sample.tv,
&ref_ticker->last_sample.tv);
- usec_delta -= driftinfo->wanted_offset;
sample_tick(xbus, usec_delta);
- if(abs(usec_delta) > 300) {
+ if ((ticker->count % SYNC_CYCLE) > (SYNC_CYCLE - SYNC_CYCLE_SAMPLE))
+ di->delta_sum += usec_delta;
+
+ if((ticker->count % SYNC_CYCLE) == 0) {
/*
- * We are close to the edge, send a brutal
- * fix, and skip calculation until next time.
+ * Full sampling cycle passed. Let's calculate
*/
- if(usec_delta > 0 && xbus->sync_adjustment > -SYNC_ADJ_MAX) {
- XBUS_DBG(SYNC, xbus, "Pullback usec_delta=%ld\n", usec_delta);
- driftinfo->kicks_down++;
- send_drift(xbus, -SYNC_ADJ_MAX); /* emergency push */
+ int offset = di->delta_sum / SYNC_CYCLE_SAMPLE - SYNC_CENTER;
+ int offset_prev = di->offset_prev;
+ int speed = xbus->sync_adjustment;
+ int fix = 0;
+ int best_speed = (di->max_speed + di->min_speed) >> 1;
+
+ if (offset > 0 && offset < SYNC_DELTA) {
+ speed = best_speed - 1;
+ } else if (offset < 0 && offset > -SYNC_DELTA) {
+ speed = best_speed + 1;
+ } else {
+ if (offset > 0) {
+ if (offset > offset_prev)
+ fix--;
+ } else {
+ if (offset < offset_prev)
+ fix++;
+ }
+ speed += fix;
}
- if(usec_delta < 0 && xbus->sync_adjustment < SYNC_ADJ_MAX) {
- XBUS_DBG(SYNC, xbus, "Pushback usec_delta=%ld\n", usec_delta);
- driftinfo->kicks_up++;
- send_drift(xbus, SYNC_ADJ_MAX); /* emergency push */
+ if (speed < -SYNC_ADJ_MAX)
+ speed = -SYNC_ADJ_MAX;
+ if (speed > SYNC_ADJ_MAX)
+ speed = SYNC_ADJ_MAX;
+ if (speed < di->min_speed)
+ di->min_speed = speed;
+ if (speed > di->max_speed)
+ di->max_speed = speed;
+ if(offset > di->offset_max)
+ di->offset_max = offset;
+ if(offset < di->offset_min)
+ di->offset_min = offset;
+
+ XBUS_DBG(SYNC, xbus, "offset: %d, min_speed=%d, max_speed=%d, usec_delta(last)=%ld\n",
+ offset_prev, di->min_speed, di->max_speed, usec_delta);
+ XBUS_DBG(SYNC, xbus, "ADJ: speed=%d (best_speed=%d) fix=%d\n",
+ speed, best_speed, fix);
+ xbus->sync_adjustment_offset = speed;
+ if(xbus != syncer && xbus->sync_adjustment != speed)
+ send_drift(xbus, speed);
+ di->sync_inaccuracy = abs(offset) + abs(di->offset_range) / 2;
+ if(ticker->count >= SYNC_CYCLE * SYNC_CONVERGE) {
+ di->offset_range = di->offset_max - di->offset_min;
+ di->offset_min = INT_MAX;
+ di->offset_max = -INT_MAX;
+ if(di->max_speed > best_speed)
+ di->max_speed--;
+ if(di->min_speed < best_speed)
+ di->min_speed++;
}
- ticker_set_cycle(ticker, SYNC_ADJ_QUICK);
- nofix = 1;
- } else {
- /* good data, use it */
- if(usec_delta > driftinfo->delta_max)
- driftinfo->delta_max = usec_delta;
- if(usec_delta < driftinfo->delta_min)
- driftinfo->delta_min = usec_delta;
+ di->offset_prev = offset;
+ di->delta_sum = 0;
}
- if(!nofix && cycled) {
- int offset = 0;
-
- driftinfo->median = (driftinfo->delta_max + driftinfo->delta_min) / 2;
- driftinfo->jitter = driftinfo->delta_max - driftinfo->delta_min;
- if(abs(driftinfo->median) >= 150) { /* more than 1 usb uframe */
- int factor = abs(driftinfo->median) / 125;
-
- factor = 1 + (factor * 8000) / ticker->cycle;
- if(driftinfo->median > 0)
- offset = driftinfo->calc_drift - factor;
- else
- offset = driftinfo->calc_drift + factor;
- /* for large median, push some more */
- if(abs(driftinfo->median) >= 300) { /* more than 2 usb uframes */
- ticker_set_cycle(ticker, SYNC_ADJ_QUICK);
- XBUS_NOTICE(xbus,
- "Back to quick: median=%d\n",
- driftinfo->median);
- }
- } else {
- //ticker_set_cycle(ticker, ticker->cycle + 500);
- }
- driftinfo->calc_drift = offset;
- XBUS_DBG(SYNC, xbus,
- "ADJ: min=%d max=%d jitter=%d median=%d offset=%d\n",
- driftinfo->delta_min,
- driftinfo->delta_max,
- driftinfo->jitter,
- driftinfo->median,
- offset);
- if(offset < -SYNC_ADJ_MAX)
- offset = -SYNC_ADJ_MAX;
- if(offset > SYNC_ADJ_MAX)
- offset = SYNC_ADJ_MAX;
- xbus->sync_adjustment_offset = offset;
- if(xbus != syncer && xbus->sync_adjustment != offset)
- send_drift(xbus, offset);
- driftinfo_recalc(driftinfo);
- }
- }
- }
- spin_unlock_irqrestore(&driftinfo->lock, flags);
+ }
+ }
+ spin_unlock_irqrestore(&di->lock, flags);
}
const char *sync_mode_name(enum sync_mode mode)
Modified: linux/trunk/drivers/dahdi/xpp/xbus-pcm.h
URL: http://svnview.digium.com/svn/dahdi/linux/trunk/drivers/dahdi/xpp/xbus-pcm.h?view=diff&rev=7625&r1=7624&r2=7625
==============================================================================
--- linux/trunk/drivers/dahdi/xpp/xbus-pcm.h (original)
+++ linux/trunk/drivers/dahdi/xpp/xbus-pcm.h Sun Nov 22 15:17:16 2009
@@ -71,17 +71,18 @@
* xbus ticker to a reference ticker.
*/
struct xpp_drift {
- int wanted_offset; /* fixed */
int delta_tick; /* from ref_ticker */
int lost_ticks; /* occurances */
int lost_tick_count;
- int delta_max;
- int delta_min;
- int median; /* (max + min) / 2 */
- int jitter; /* max - min */
- int calc_drift;
- int kicks_up;
- int kicks_down;
+ int sync_inaccuracy;
+ struct xpp_timestamp last_lost_tick;
+ long delta_sum;
+ int offset_prev;
+ int offset_range;
+ int offset_min;
+ int offset_max;
+ int min_speed;
+ int max_speed;
spinlock_t lock;
};
Modified: linux/trunk/drivers/dahdi/xpp/xbus-sysfs.c
URL: http://svnview.digium.com/svn/dahdi/linux/trunk/drivers/dahdi/xpp/xbus-sysfs.c?view=diff&rev=7625&r1=7624&r2=7625
==============================================================================
--- linux/trunk/drivers/dahdi/xpp/xbus-sysfs.c (original)
+++ linux/trunk/drivers/dahdi/xpp/xbus-sysfs.c Sun Nov 22 15:17:16 2009
@@ -121,10 +121,8 @@
len += snprintf(buf + len, PAGE_SIZE - len, "%-3s", sync_mode_name(xbus->sync_mode));
if(xbus->sync_mode == SYNC_MODE_PLL) {
len += snprintf(buf + len, PAGE_SIZE - len,
- " %5d: jitter %4d median %4d calc_drift %3d lost (%4d,%4d) : ",
+ " %5d: lost (%4d,%4d) : ",
xbus->ticker.cycle,
- driftinfo->jitter, driftinfo->median,
- driftinfo->calc_drift,
driftinfo->lost_ticks, driftinfo->lost_tick_count);
len += snprintf(buf + len, PAGE_SIZE - len,
"DRIFT %3d %ld sec ago",
@@ -212,25 +210,52 @@
xbus_t *xbus;
struct xpp_drift *di;
struct xpp_ticker *ticker;
+ struct timeval now;
int len = 0;
+ int hours;
+ int minutes;
+ int seconds;
+ int speed_range;
+ int uframes_inaccuracy;
+ int i;
xbus = dev_to_xbus(dev);
di = &xbus->drift;
ticker = &xbus->ticker;
-#define SHOW(ptr,item) len += snprintf(buf + len, PAGE_SIZE - len, "%-15s: %d\n", #item, (ptr)->item)
+ /*
+ * Calculate lost ticks time
+ */
+ do_gettimeofday(&now);
+ seconds = now.tv_sec - di->last_lost_tick.tv.tv_sec;
+ minutes = seconds / 60;
+ seconds = seconds % 60;
+ hours = minutes / 60;
+ minutes = minutes % 60;
+#define SHOW(ptr,item) len += snprintf(buf + len, PAGE_SIZE - len, "%-15s: %8d\n", #item, (ptr)->item)
+ len += snprintf(buf + len, PAGE_SIZE - len, "%-15s: %8d (was %d:%02d:%02d ago)\n",
+ "lost_ticks", di->lost_ticks, hours, minutes, seconds);
+ speed_range = abs(di->max_speed - di->min_speed);
+ uframes_inaccuracy = di->sync_inaccuracy / 125;
+ len += snprintf(buf + len, PAGE_SIZE - len, "%-15s: %8d ",
+ "instability", speed_range + uframes_inaccuracy);
+ if(xbus->sync_mode == SYNC_MODE_AB) {
+ buf[len++] = '-';
+ } else {
+ for(i = 0; len < PAGE_SIZE - 1 && i < speed_range + uframes_inaccuracy; i++)
+ buf[len++] = '#';
+ }
+ buf[len++] = '\n';
+ len += snprintf(buf + len, PAGE_SIZE - len, "%-15s: %8d (uframes)\n", "inaccuracy", uframes_inaccuracy);
+ len += snprintf(buf + len, PAGE_SIZE - len, "%-15s: %8d\n", "speed_range", speed_range);
SHOW(xbus, sync_adjustment);
- SHOW(di, wanted_offset);
- SHOW(di, delta_tick);
- SHOW(di, lost_ticks);
- SHOW(di, kicks_up);
- SHOW(di, kicks_down);
- SHOW(di, delta_min);
- SHOW(di, delta_max);
- SHOW(di, median);
- SHOW(di, jitter);
- SHOW(di, calc_drift);
+ len += snprintf(buf + len, PAGE_SIZE - len, "%-15s: %8d\n", "offset (usec)", di->offset_prev);
+ SHOW(di, offset_range);
+ len += snprintf(buf + len, PAGE_SIZE - len, "%-15s: %8d\n", "best_speed", (di->max_speed + di->min_speed) / 2);
+ SHOW(di, min_speed);
+ SHOW(di, max_speed);
SHOW(ticker, cycle);
SHOW(ticker, tick_period);
+ SHOW(ticker, count);
#undef SHOW
return len;
}
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