trigger/hrt: fix sysfs value propagation

The HRT trigger has a bug. If you program the fire in the past, the trigger fires immediately, so ZIO has not the time to propagate the sysfs value to the current_control. The result is that the acquired block has the wrong value for attribute exp_{sec|scalar_h}. The patch introduces a fire delay of 100ms when you program the trigger in the past. This allows ZIO to propagate the sysfs values. I am aware that 100ms can be a long time, but it does not matter because the expected fire should be in the past and it is not possible. Moreover, the cosistency of the control information will provide information about the expected fire which is more important than rapidity of a wrong the fire. --------------------------------------------------------------------- echo 3 > /sys/bus/zio/devices/zzero-0000/zero-input-32/trigger/exp-scalar-h echo 4 > /sys/bus/zio/devices/zzero-0000/zero-input-32/trigger/exp-scalar-h [ 1432.799476] zattr_store [ 1432.799762] trigger: writing value 3 to sysfs attribute exp-scalar-h [ 1432.800183] ztt_conf_set:81 [ 1432.800466] ztt_conf_set:146 [ 1432.800846] ztt_fn:167 [ 1432.801162] zio_arm_trigger:131 [ 1432.801162] __zio_arm_input_trigger:82 [ 1432.801162] zbk_alloc_block:94 [ 1432.801162] zio_generic_data_done:135 [ 1432.801162] zbk_store_block:172 (ffff88000d4ebc00, ffff88000d40dd80) [ 1432.803739] __zattr_propagate_value [ 1435.736568] zattr_store [ 1435.737977] trigger: writing value 4 to sysfs attribute exp-scalar-h [ 1435.739315] ztt_conf_set:81 [ 1435.740881] ztt_conf_set:146 [ 1435.742389] ztt_fn:167 [ 1435.743381] zio_arm_trigger:131 [ 1435.743381] __zio_arm_input_trigger:82 [ 1435.743381] zbk_alloc_block:94 [ 1435.743381] zio_generic_data_done:135 [ 1435.743381] zbk_store_block:172 (ffff88000d4ebc00, ffff88000d40df40) [ 1435.747783] __zattr_propagate_value From zio-dump block 1 - "Ctrl: trigger-ext-5 0x00000002 2" block 2 - "Ctrl: trigger-ext-5 0x00000003 3" --------------------------------------------------------------------- Signed-off-by: Federico Vaga <federico.vaga@gmail.com>

trigger/hrt: fix sysfs value propagation
The HRT trigger has a bug. If you program the fire in the past, the trigger fires immediately, so ZIO has not the time to propagate the sysfs value to the current_control. The result is that the acquired block has the wrong value for attribute exp_{sec|scalar_h}. The patch introduces a fire delay of 100ms when you program the trigger in the past. This allows ZIO to propagate the sysfs values. I am aware that 100ms can be a long time, but it does not matter because the expected fire should be in the past and it is not possible. Moreover, the cosistency of the control information will provide information about the expected fire which is more important than rapidity of a wrong the fire. --------------------------------------------------------------------- echo 3 > /sys/bus/zio/devices/zzero-0000/zero-input-32/trigger/exp-scalar-h echo 4 > /sys/bus/zio/devices/zzero-0000/zero-input-32/trigger/exp-scalar-h [ 1432.799476] zattr_store [ 1432.799762] trigger: writing value 3 to sysfs attribute exp-scalar-h [ 1432.800183] ztt_conf_set:81 [ 1432.800466] ztt_conf_set:146 [ 1432.800846] ztt_fn:167 [ 1432.801162] zio_arm_trigger:131 [ 1432.801162] __zio_arm_input_trigger:82 [ 1432.801162] zbk_alloc_block:94 [ 1432.801162] zio_generic_data_done:135 [ 1432.801162] zbk_store_block:172 (ffff88000d4ebc00, ffff88000d40dd80) [ 1432.803739] __zattr_propagate_value [ 1435.736568] zattr_store [ 1435.737977] trigger: writing value 4 to sysfs attribute exp-scalar-h [ 1435.739315] ztt_conf_set:81 [ 1435.740881] ztt_conf_set:146 [ 1435.742389] ztt_fn:167 [ 1435.743381] zio_arm_trigger:131 [ 1435.743381] __zio_arm_input_trigger:82 [ 1435.743381] zbk_alloc_block:94 [ 1435.743381] zio_generic_data_done:135 [ 1435.743381] zbk_store_block:172 (ffff88000d4ebc00, ffff88000d40df40) [ 1435.747783] __zattr_propagate_value From zio-dump block 1 - "Ctrl: trigger-ext-5 0x00000002 2" block 2 - "Ctrl: trigger-ext-5 0x00000003 3" --------------------------------------------------------------------- Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
fe50c546 · Federico Vaga · 765ffa86 · fe50c546
Commit fe50c546 authored Feb 05, 2014 by Federico Vaga
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Showing with 21 additions and 3 deletions

zio-trig-hrt.c triggers/zio-trig-hrt.c +21 -3

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--- a/triggers/zio-trig-hrt.c
+++ b/triggers/zio-trig-hrt.c
@@ -75,6 +75,7 @@ static int ztt_conf_set(struct device *dev, struct zio_attribute *zattr,
 	struct zio_ti *ti = to_zio_ti(dev);
 	struct ztt_instance *ztt = to_ztt_instance(ti);
 	struct timespec now;
+	uint64_t now_ns;
 	ktime_t ktime;

 	pr_debug("%s:%d\n", __func__, __LINE__);
@@ -97,12 +98,17 @@ static int ztt_conf_set(struct device *dev, struct zio_attribute *zattr,
 		ztt->ts.tv_nsec = usr_val;
 		break;
 	case ZTT_ATTR_EXP_SEC:
+		getnstimeofday(&now);
+
 		if (usr_val < 10) {
-			getnstimeofday(&now);
 			usr_val += now.tv_sec;
 		}
 		ztt->ts.tv_sec = usr_val;
 		ztt->scalar = ztt->ts.tv_sec * NSEC_PER_SEC + ztt->ts.tv_nsec;
+		if (ztt->ts.tv_sec < now.tv_sec) {
+			/* Read comment in ZTT_ATTR_EXP_SCALAR_H */
+			ztt->scalar += 100000000;
+		}
 		ktime = timespec_to_ktime(ztt->ts),
 		ztt->flags |= ZTT_FLAGS_PENDING;
 		hrtimer_start_range_ns(&ztt->timer, ktime, ztt->slack,
@@ -117,10 +123,22 @@ static int ztt_conf_set(struct device *dev, struct zio_attribute *zattr,
 		ztt->scalar_l = usr_val;
 		break;
 	case ZTT_ATTR_EXP_SCALAR_H:
+		getnstimeofday(&now);
+		now_ns = ktime_to_ns(timespec_to_ktime(now));
+
 		ztt->scalar = (uint64_t)usr_val << 32 | ztt->scalar_l;
 		if (!usr_val) {
-			getnstimeofday(&now);
-			ztt->scalar += ktime_to_ns(timespec_to_ktime(now));
+			/* Use relative time */
+			ztt->scalar += now_ns;
+		} else if (ztt->scalar < now_ns) {
+			/*
+			 * The trigger is programmed in the past. Add a
+			 * delay of 100ms in order to allow the ZIO core
+			 * to propagate the value to the current control.
+			 *
+			 * NOTE: More details in commit message
+			 */
+			ztt->scalar = now_ns + 100000000;
 		}
 		ktime = ns_to_ktime(ztt->scalar);
 		ztt->flags |= ZTT_FLAGS_PENDING;