rework sensor tasks to use the kernels generic workq rather than a special

kernel thread of its own. the api has changed (which will be fixed in the
manpage shortly) so all the users of sensor tasks that i can find have
been fixed too.

noone tested, so its going in to force people to run with it.
"put it in" deraadt@

34 files changed, 185 insertions, 178 deletions

diff --git a/sys/arch/macppc/dev/asms.c b/sys/arch/macppc/dev/asms.c
index 9937a890483..50621c33179 100644
--- a/sys/arch/macppc/dev/asms.c
+++ b/sys/arch/macppc/dev/asms.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: asms.c,v 1.5 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: asms.c,v 1.6 2007/06/24 05:34:35 dlg Exp $	*/
 /*
  * Copyright (c) 2005 Xavier Santolaria <xsa@openbsd.org>
  *
@@ -263,7 +263,7 @@ asms_attach(struct device *parent, struct device *self, void *aux)
 	strlcpy(sc->sc_sensor[ASMS_DATA_Z].desc, "Z_ACCEL",
 	    sizeof(sc->sc_sensor[ASMS_DATA_Z].desc));
 
-	if (sensor_task_register(sc, asms_refresh, 5)) {
+	if (sensor_task_register(sc, asms_refresh, 5) == NULL) {
 		printf(": unable to register update task\n");
 		return;
 	}
diff --git a/sys/arch/sparc64/dev/pcf8591_ofw.c b/sys/arch/sparc64/dev/pcf8591_ofw.c
index 9c637732dc9..b93297a03c6 100644
--- a/sys/arch/sparc64/dev/pcf8591_ofw.c
+++ b/sys/arch/sparc64/dev/pcf8591_ofw.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcf8591_ofw.c,v 1.3 2007/03/22 16:55:31 deraadt Exp $ */
+/*	$OpenBSD: pcf8591_ofw.c,v 1.4 2007/06/24 05:34:35 dlg Exp $ */
 
 /*
  * Copyright (c) 2006 Damien Miller <djm@openbsd.org>
@@ -178,7 +178,7 @@ pcfadc_attach(struct device *parent, struct device *self, void *aux)
 			sensor_attach(&sc->sc_sensordev, 
 			    &sc->sc_channels[i].chan_sensor);
 
-	if (sensor_task_register(sc, pcfadc_refresh, 5)) {
+	if (sensor_task_register(sc, pcfadc_refresh, 5) == NULL) {
 		printf(": unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/ad741x.c b/sys/dev/i2c/ad741x.c
index 0c82851cfa8..75810de22ac 100644
--- a/sys/dev/i2c/ad741x.c
+++ b/sys/dev/i2c/ad741x.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ad741x.c,v 1.11 2007/04/09 19:31:22 kettenis Exp $	*/
+/*	$OpenBSD: ad741x.c,v 1.12 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -139,7 +139,7 @@ adc_attach(struct device *parent, struct device *self, void *aux)
 		nsens += 3;
 	}
 
-	if (sensor_task_register(sc, adc_refresh, 5)) {
+	if (sensor_task_register(sc, adc_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/adm1021.c b/sys/dev/i2c/adm1021.c
index b8f44afe0d9..e49e67b1215 100644
--- a/sys/dev/i2c/adm1021.c
+++ b/sys/dev/i2c/adm1021.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: adm1021.c,v 1.26 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: adm1021.c,v 1.27 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -151,7 +151,7 @@ admtemp_attach(struct device *parent, struct device *self, void *aux)
 	    xeon ? "Xeon" : "Internal",
 	    sizeof(sc->sc_sensor[ADMTEMP_INT].desc));
 
-	if (sensor_task_register(sc, admtemp_refresh, 5)) {
+	if (sensor_task_register(sc, admtemp_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/adm1024.c b/sys/dev/i2c/adm1024.c
index 630cc3cdec6..e826660e4b5 100644
--- a/sys/dev/i2c/adm1024.c
+++ b/sys/dev/i2c/adm1024.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: adm1024.c,v 1.13 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: adm1024.c,v 1.14 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -171,7 +171,7 @@ admlc_attach(struct device *parent, struct device *self, void *aux)
 	sc->sc_sensor[ADMLC_FAN2].type = SENSOR_FANRPM;
 
 
-	if (sensor_task_register(sc, admlc_refresh, 5)) {
+	if (sensor_task_register(sc, admlc_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/adm1025.c b/sys/dev/i2c/adm1025.c
index 911c8398203..5a92ab081b7 100644
--- a/sys/dev/i2c/adm1025.c
+++ b/sys/dev/i2c/adm1025.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: adm1025.c,v 1.24 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: adm1025.c,v 1.25 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -179,7 +179,7 @@ admtm_attach(struct device *parent, struct device *self, void *aux)
 	strlcpy(sc->sc_sensor[SMSC_TEMP2].desc, "External",
 	    sizeof(sc->sc_sensor[SMSC_TEMP2].desc));
 
-	if (sensor_task_register(sc, admtm_refresh, 5)) {
+	if (sensor_task_register(sc, admtm_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/adm1026.c b/sys/dev/i2c/adm1026.c
index 26cea62b63e..4b5deeb0534 100644
--- a/sys/dev/i2c/adm1026.c
+++ b/sys/dev/i2c/adm1026.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: adm1026.c,v 1.9 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: adm1026.c,v 1.10 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -213,7 +213,7 @@ admcts_attach(struct device *parent, struct device *self, void *aux)
 	sc->sc_sensor[ADMCTS_FAN6].type = SENSOR_FANRPM;
 	sc->sc_sensor[ADMCTS_FAN7].type = SENSOR_FANRPM;
 
-	if (sensor_task_register(sc, admcts_refresh, 5)) {
+	if (sensor_task_register(sc, admcts_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/adm1030.c b/sys/dev/i2c/adm1030.c
index 3e8f9ee7aca..cbabb569097 100644
--- a/sys/dev/i2c/adm1030.c
+++ b/sys/dev/i2c/adm1030.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: adm1030.c,v 1.7 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: adm1030.c,v 1.8 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -102,7 +102,7 @@ admtmp_attach(struct device *parent, struct device *self, void *aux)
 
 	sc->sc_sensor[ADMTMP_FAN].type = SENSOR_FANRPM;
 
-	if (sensor_task_register(sc, admtmp_refresh, 5)) {
+	if (sensor_task_register(sc, admtmp_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/adm1031.c b/sys/dev/i2c/adm1031.c
index cdbc443e71d..0bf9dd54af3 100644
--- a/sys/dev/i2c/adm1031.c
+++ b/sys/dev/i2c/adm1031.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: adm1031.c,v 1.7 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: adm1031.c,v 1.8 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -112,7 +112,7 @@ admtt_attach(struct device *parent, struct device *self, void *aux)
 
 	sc->sc_sensor[ADMTT_FAN2].type = SENSOR_FANRPM;
 
-	if (sensor_task_register(sc, admtt_refresh, 5)) {
+	if (sensor_task_register(sc, admtt_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/adt7460.c b/sys/dev/i2c/adt7460.c
index 52d2ce85247..afaeac888a8 100644
--- a/sys/dev/i2c/adt7460.c
+++ b/sys/dev/i2c/adt7460.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: adt7460.c,v 1.17 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: adt7460.c,v 1.18 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Mark Kettenis
@@ -231,7 +231,7 @@ adt_attach(struct device *parent, struct device *self, void *aux)
 	sc->sc_sensor[ADT_TACH3].type = SENSOR_FANRPM;
 	sc->sc_sensor[ADT_TACH4].type = SENSOR_FANRPM;
 
-	if (sensor_task_register(sc, adt_refresh, 5)) {
+	if (sensor_task_register(sc, adt_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/asb100.c b/sys/dev/i2c/asb100.c
index 43759eab6dc..37961c82ece 100644
--- a/sys/dev/i2c/asb100.c
+++ b/sys/dev/i2c/asb100.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: asb100.c,v 1.9 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: asb100.c,v 1.10 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Damien Miller <djm@openbsd.org>
@@ -258,7 +258,7 @@ asbtm_attach(struct device *parent, struct device *self, void *aux)
 	strlcpy(sc->sc_sensor[ASB100_SENSOR_TEMP3].desc, "External",
 	    sizeof(sc->sc_sensor[ASB100_SENSOR_TEMP3].desc));
 
-	if (sensor_task_register(sc, asbtm_refresh, 5)) {
+	if (sensor_task_register(sc, asbtm_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/ds1631.c b/sys/dev/i2c/ds1631.c
index 0eeb55f8b8b..c0a911dcff3 100644
--- a/sys/dev/i2c/ds1631.c
+++ b/sys/dev/i2c/ds1631.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ds1631.c,v 1.8 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: ds1631.c,v 1.9 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -120,7 +120,7 @@ dostart:
 	strlcpy(sc->sc_sensor[MAXDS_TEMP].desc, "Internal",
 	    sizeof(sc->sc_sensor[MAXDS_TEMP].desc));
 
-	if (sensor_task_register(sc, maxds_refresh, 5)) {
+	if (sensor_task_register(sc, maxds_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/fcu.c b/sys/dev/i2c/fcu.c
index ea2ec733291..3d93aa5649f 100644
--- a/sys/dev/i2c/fcu.c
+++ b/sys/dev/i2c/fcu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fcu.c,v 1.6 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: fcu.c,v 1.7 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Mark Kettenis
@@ -98,7 +98,7 @@ fcu_attach(struct device *parent, struct device *self, void *aux)
 		    sizeof(sc->sc_sensor[FCU_PWM1 + i].desc));
 	}
 
-	if (sensor_task_register(sc, fcu_refresh, 5)) {
+	if (sensor_task_register(sc, fcu_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/fintek.c b/sys/dev/i2c/fintek.c
index 7ad803d5ebb..2fb24d0fe4c 100644
--- a/sys/dev/i2c/fintek.c
+++ b/sys/dev/i2c/fintek.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fintek.c,v 1.5 2007/03/22 16:55:31 deraadt Exp $ */
+/*	$OpenBSD: fintek.c,v 1.6 2007/06/24 05:34:35 dlg Exp $ */
 /*
  * Copyright (c) 2006 Dale Rahn <drahn@openbsd.org>
  *
@@ -155,7 +155,7 @@ fintek_attach(struct device *parent, struct device *self, void *aux)
 	sc->sc_sensor[F_FAN1].type = SENSOR_FANRPM;
 	sc->sc_sensor[F_FAN2].type = SENSOR_FANRPM;
 
-	if (sensor_task_register(sc, fintek_refresh, 5)) {
+	if (sensor_task_register(sc, fintek_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/gl518sm.c b/sys/dev/i2c/gl518sm.c
index d92cccab043..d1c00429014 100644
--- a/sys/dev/i2c/gl518sm.c
+++ b/sys/dev/i2c/gl518sm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gl518sm.c,v 1.5 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: gl518sm.c,v 1.6 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2006 Mark Kettenis
@@ -155,7 +155,7 @@ glenv_attach(struct device *parent, struct device *self, void *aux)
 	if (sc->sc_fan2_div == -1)
 		sc->sc_sensor[GLENV_FAN2].flags |= SENSOR_FINVALID;
 
-	if (sensor_task_register(sc, glenv_refresh, 5)) {
+	if (sensor_task_register(sc, glenv_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/lm87.c b/sys/dev/i2c/lm87.c
index 038b7d50961..1ecf04d2c7a 100644
--- a/sys/dev/i2c/lm87.c
+++ b/sys/dev/i2c/lm87.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lm87.c,v 1.18 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: lm87.c,v 1.19 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Mark Kettenis
@@ -223,7 +223,7 @@ lmenv_attach(struct device *parent, struct device *self, void *aux)
 		sc->sc_sensor[LMENV_FAN2].type = SENSOR_FANRPM;
 	}
 
-	if (sensor_task_register(sc, lmenv_refresh, 5)) {
+	if (sensor_task_register(sc, lmenv_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/maxim6690.c b/sys/dev/i2c/maxim6690.c
index f8448595d13..085aaff18cc 100644
--- a/sys/dev/i2c/maxim6690.c
+++ b/sys/dev/i2c/maxim6690.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: maxim6690.c,v 1.14 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: maxim6690.c,v 1.15 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -132,7 +132,7 @@ maxtmp_attach(struct device *parent, struct device *self, void *aux)
 	strlcpy(sc->sc_sensor[MAXTMP_EXT].desc, "External",
 	    sizeof(sc->sc_sensor[MAXTMP_EXT].desc));
 
-	if (sensor_task_register(sc, maxtmp_refresh, 5)) {
+	if (sensor_task_register(sc, maxtmp_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/pca9554.c b/sys/dev/i2c/pca9554.c
index dae1db08d55..473c3563f65 100644
--- a/sys/dev/i2c/pca9554.c
+++ b/sys/dev/i2c/pca9554.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pca9554.c,v 1.10 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: pca9554.c,v 1.11 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -129,7 +129,7 @@ pcagpio_attach(struct device *parent, struct device *self, void *aux)
 
 	}
 
-	if (sensor_task_register(sc, pcagpio_refresh, 5)) {
+	if (sensor_task_register(sc, pcagpio_refresh, 5) == NULL) {
 		printf(", unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/tsl2560.c b/sys/dev/i2c/tsl2560.c
index 967981acfd9..d5a5665c5b5 100644
--- a/sys/dev/i2c/tsl2560.c
+++ b/sys/dev/i2c/tsl2560.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tsl2560.c,v 1.5 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: tsl2560.c,v 1.6 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 Mark Kettenis
@@ -120,7 +120,7 @@ tsl_attach(struct device *parent, struct device *self, void *aux)
 	    sizeof(sc->sc_sensordev.xname));
 	sc->sc_sensor.type = SENSOR_LUX;
 
-	if (sensor_task_register(sc, tsl_refresh, 5)) {
+	if (sensor_task_register(sc, tsl_refresh, 5) == NULL) {
 		printf(": unable to register update task\n");
 		return;
 	}
diff --git a/sys/dev/i2c/w83l784r.c b/sys/dev/i2c/w83l784r.c
index 9795bab4aef..0b33f8a432e 100644
--- a/sys/dev/i2c/w83l784r.c
+++ b/sys/dev/i2c/w83l784r.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: w83l784r.c,v 1.11 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: w83l784r.c,v 1.12 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2006 Mark Kettenis
@@ -219,7 +219,7 @@ wbenv_attach(struct device *parent, struct device *self, void *aux)
 	iic_ignore_addr(sc->sc_addr[2]);
 
  start:
-	if (sensor_task_register(sc, wbenv_refresh, 5)) {
+	if (sensor_task_register(sc, wbenv_refresh, 5) == NULL) {
 		printf("%s: unable to register update task\n",
 		    sc->sc_dev.dv_xname);
 		return;
diff --git a/sys/dev/ic/ami.c b/sys/dev/ic/ami.c
index a4f558d30a0..d1a46b97a5d 100644
--- a/sys/dev/ic/ami.c
+++ b/sys/dev/ic/ami.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ami.c,v 1.183 2007/05/31 18:39:03 dlg Exp $	*/
+/*	$OpenBSD: ami.c,v 1.184 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2001 Michael Shalayeff
@@ -2474,7 +2474,7 @@ ami_create_sensors(struct ami_softc *sc)
 	if (sc->sc_bd == NULL)
 		goto bad;
 
-	if (sensor_task_register(sc, ami_refresh_sensors, 10) != 0)
+	if (sensor_task_register(sc, ami_refresh_sensors, 10) == NULL)
 		goto freebd;
 
 	sensordev_install(&sc->sc_sensordev);
diff --git a/sys/dev/ic/ciss.c b/sys/dev/ic/ciss.c
index bb229a41e76..260872fc2ba 100644
--- a/sys/dev/ic/ciss.c
+++ b/sys/dev/ic/ciss.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ciss.c,v 1.26 2007/05/29 22:17:50 todd Exp $	*/
+/*	$OpenBSD: ciss.c,v 1.27 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005,2006 Michael Shalayeff
@@ -438,7 +438,7 @@ ciss_attach(struct ciss_softc *sc)
 			    scsibus->sc_link[i][0]->device_softc)->dv_xname,
 			    sizeof(sc->sc_lds[i]->xname));
 		}
-		if (sensor_task_register(sc, ciss_sensors, 10))
+		if (sensor_task_register(sc, ciss_sensors, 10) == NULL)
 			free(sc->sensors, M_DEVBUF);
 		else
 			sensordev_install(&sc->sensordev);
diff --git a/sys/dev/ic/lm78.c b/sys/dev/ic/lm78.c
index b55567be46e..7323beecb52 100644
--- a/sys/dev/ic/lm78.c
+++ b/sys/dev/ic/lm78.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lm78.c,v 1.18 2007/05/26 22:47:39 cnst Exp $	*/
+/*	$OpenBSD: lm78.c,v 1.19 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005, 2006 Mark Kettenis
@@ -399,7 +399,8 @@ lm_attach(struct lm_softc *sc)
 	if (sc->numsensors == 0)
 		return;
 
-	if (sensor_task_register(sc, lm_refresh, 5)) {
+	sc->sensortask = sensor_task_register(sc, lm_refresh, 5);
+	if (sc->sensortask == NULL) {
 		printf("%s: unable to register update task\n",
 		    sc->sc_dev.dv_xname);
 		return;
@@ -425,7 +426,8 @@ lm_detach(struct lm_softc *sc)
 	for (i = 0; i < sc->numsensors; i++)
 		sensor_detach(&sc->sensordev, &sc->sensors[i]);
 
-	sensor_task_unregister(sc);
+	if (sc->sensortask != NULL)
+		sensor_task_unregister(sc->sensortask);
 
 	return 0;
 }
diff --git a/sys/dev/ic/lm78var.h b/sys/dev/ic/lm78var.h
index 6ea9697e843..7ab9437bd16 100644
--- a/sys/dev/ic/lm78var.h
+++ b/sys/dev/ic/lm78var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lm78var.h,v 1.12 2007/05/25 02:26:43 cnst Exp $	*/
+/*	$OpenBSD: lm78var.h,v 1.13 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005, 2006 Mark Kettenis
@@ -140,6 +140,7 @@ struct lm_softc {
 
 	struct ksensor sensors[WB_MAX_SENSORS];
 	struct ksensordev sensordev;
+	struct sensor_task *sensortask;
 	struct lm_sensor *lm_sensors;
 	u_int numsensors;
 	void (*refresh_sensor_data) (struct lm_softc *);
diff --git a/sys/dev/ic/mfi.c b/sys/dev/ic/mfi.c
index 0ed0ee857b9..05c404bdca1 100644
--- a/sys/dev/ic/mfi.c
+++ b/sys/dev/ic/mfi.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mfi.c,v 1.72 2007/05/29 22:17:50 todd Exp $ */
+/* $OpenBSD: mfi.c,v 1.73 2007/06/24 05:34:35 dlg Exp $ */
 /*
  * Copyright (c) 2006 Marco Peereboom <marco@peereboom.us>
  *
@@ -1817,7 +1817,7 @@ mfi_create_sensors(struct mfi_softc *sc)
 		sensor_attach(&sc->sc_sensordev, &sc->sc_sensors[i]);
 	}
 
-	if (sensor_task_register(sc, mfi_refresh_sensors, 10) != 0)
+	if (sensor_task_register(sc, mfi_refresh_sensors, 10) == NULL)
 		goto bad;
 
 	sensordev_install(&sc->sc_sensordev);
diff --git a/sys/dev/isa/it.c b/sys/dev/isa/it.c
index 63583a3ddbf..79c51ac1baa 100644
--- a/sys/dev/isa/it.c
+++ b/sys/dev/isa/it.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: it.c,v 1.22 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: it.c,v 1.23 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2003 Julien Bordet <zejames@greyhats.org>
@@ -155,7 +155,7 @@ it_attach(struct device *parent, struct device *self, void *aux)
 	it_setup_volt(sc, 3, 9);
 	it_setup_temp(sc, 12, 3);
 
-	if (sensor_task_register(sc, it_refresh, 5)) {
+	if (sensor_task_register(sc, it_refresh, 5) == NULL) {
 		printf("%s: unable to register update task\n",
 		    sc->sc_dev.dv_xname);
 		return;
diff --git a/sys/dev/onewire/owsbm.c b/sys/dev/onewire/owsbm.c
index 8bbb7e5c5be..3f6ef634f2a 100644
--- a/sys/dev/onewire/owsbm.c
+++ b/sys/dev/onewire/owsbm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: owsbm.c,v 1.3 2007/06/01 23:35:00 cnst Exp $	*/
+/*	$OpenBSD: owsbm.c,v 1.4 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2007 Aaron Linville <aaron@linville.org>
@@ -69,6 +69,8 @@ struct owsbm_softc {
 	struct ksensor		sc_voltage_vad; /* General purpose, AD = 0 */
 	struct ksensor		sc_voltage_cr; /* Current Register */
 
+	struct sensor_task	*sc_sensortask;
+
 	struct rwlock		sc_lock;
 };
 
@@ -132,7 +134,8 @@ owsbm_attach(struct device *parent, struct device *self, void *aux)
 	strlcpy(sc->sc_voltage_cr.desc, "CR", sizeof(sc->sc_voltage_cr.desc));
 	sensor_attach(&sc->sc_sensordev, &sc->sc_voltage_cr);
 
-	if (sensor_task_register(sc, owsbm_update, 10)) {
+	sc->sc_sensortask = sensor_task_register(sc, owsbm_update, 10);
+	if (sc->sc_sensortask == NULL) {
 		printf(": unable to register owsbm update task\n");
 		return;
 	}
@@ -150,7 +153,8 @@ owsbm_detach(struct device *self, int flags)
 
 	rw_enter_write(&sc->sc_lock);
 	sensordev_deinstall(&sc->sc_sensordev);
-	sensor_task_unregister(sc);
+	if (sc->sc_sensortask != NULL)
+		sensor_task_unregister(sc->sc_sensortask);
 	rw_exit_write(&sc->sc_lock);
 
 	return (0);
diff --git a/sys/dev/onewire/owtemp.c b/sys/dev/onewire/owtemp.c
index 47f78c67612..29250ff918f 100644
--- a/sys/dev/onewire/owtemp.c
+++ b/sys/dev/onewire/owtemp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: owtemp.c,v 1.7 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: owtemp.c,v 1.8 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
@@ -53,6 +53,7 @@ struct owtemp_softc {
 
 	struct ksensor		sc_sensor;
 	struct ksensordev	sc_sensordev;
+	struct sensor_task	*sc_sensortask;
 	struct rwlock		sc_lock;
 };
 
@@ -100,7 +101,8 @@ owtemp_attach(struct device *parent, struct device *self, void *aux)
 	    sizeof(sc->sc_sensordev.xname));
 	sc->sc_sensor.type = SENSOR_TEMP;
 
-	if (sensor_task_register(sc, owtemp_update, 5)) {
+	sc->sc_sensortask = sensor_task_register(sc, owtemp_update, 5);
+	if (sc->sc_sensortask == NULL) {
 		printf(": unable to register update task\n");
 		return;
 	}
@@ -118,7 +120,8 @@ owtemp_detach(struct device *self, int flags)
 
 	rw_enter_write(&sc->sc_lock);
 	sensordev_deinstall(&sc->sc_sensordev);
-	sensor_task_unregister(sc);
+	if (sc->sc_sensortask != NULL)
+		sensor_task_unregister(sc->sc_sensortask);
 	rw_exit_write(&sc->sc_lock);
 
 	return (0);
diff --git a/sys/dev/pci/arc.c b/sys/dev/pci/arc.c
index a651bc44365..bb349144315 100644
--- a/sys/dev/pci/arc.c
+++ b/sys/dev/pci/arc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc.c,v 1.63 2007/05/29 22:17:50 todd Exp $ */
+/*	$OpenBSD: arc.c,v 1.64 2007/06/24 05:34:35 dlg Exp $ */
 
 /*
  * Copyright (c) 2006 David Gwynne <dlg@openbsd.org>
@@ -1564,7 +1564,7 @@ arc_create_sensors(void *xsc, void *arg)
 		sensor_attach(&sc->sc_sensordev, &sc->sc_sensors[i]);
 	}
 
-	if (sensor_task_register(sc, arc_refresh_sensors, 120) != 0)
+	if (sensor_task_register(sc, arc_refresh_sensors, 120) == NULL)
 		goto bad;
 
 	sensordev_install(&sc->sc_sensordev);
diff --git a/sys/dev/softraid.c b/sys/dev/softraid.c
index a169e83f7b0..4f16fcaf6e3 100644
--- a/sys/dev/softraid.c
+++ b/sys/dev/softraid.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: softraid.c,v 1.81 2007/06/06 23:06:02 deraadt Exp $ */
+/* $OpenBSD: softraid.c,v 1.82 2007/06/24 05:34:35 dlg Exp $ */
 /*
  * Copyright (c) 2007 Marco Peereboom <marco@peereboom.us>
  *
@@ -2362,7 +2362,7 @@ sr_create_sensors(struct sr_discipline *sd)
 	sensor_attach(&sd->sd_vol.sv_sensordev, &sd->sd_vol.sv_sensor);
 
 	if (sc->sc_sensors_running == 0) {
-		if (sensor_task_register(sc, sr_refresh_sensors, 10) != 0)
+		if (sensor_task_register(sc, sr_refresh_sensors, 10) == NULL)
 			goto bad;
 		sc->sc_sensors_running = 1;
 	}
diff --git a/sys/kern/kern_sensors.c b/sys/kern/kern_sensors.c
index 798cd7789b5..54384ee0e0a 100644
--- a/sys/kern/kern_sensors.c
+++ b/sys/kern/kern_sensors.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sensors.c,v 1.19 2007/06/04 18:42:05 deraadt Exp $	*/
+/*	$OpenBSD: kern_sensors.c,v 1.20 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2005 David Gwynne <dlg@openbsd.org>
@@ -18,37 +18,23 @@
  */
 
 #include <sys/param.h>
+#include <sys/proc.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/malloc.h>
-#include <sys/kthread.h>
 #include <sys/queue.h>
 #include <sys/types.h>
-#include <sys/time.h>
 #include <sys/device.h>
 #include <sys/hotplug.h>
+#include <sys/timeout.h>
+#include <sys/workq.h>
 
 #include <sys/sensors.h>
 #include "hotplug.h"
 
 int			sensordev_count = 0;
-SLIST_HEAD(, ksensordev) sensordev_list = SLIST_HEAD_INITIALIZER(sensordev_list);
-
-struct sensor_task {
-	void				*arg;
-	void				(*func)(void *);
-
-	int				period;
-	time_t				nextrun;
-	volatile int			running;
-	TAILQ_ENTRY(sensor_task)	entry;
-};
-
-void	sensor_task_create(void *);
-void	sensor_task_thread(void *);
-void	sensor_task_schedule(struct sensor_task *);
-
-TAILQ_HEAD(, sensor_task) tasklist = TAILQ_HEAD_INITIALIZER(tasklist);
+SLIST_HEAD(, ksensordev) sensordev_list =
+    SLIST_HEAD_INITIALIZER(sensordev_list);
 
 void
 sensordev_install(struct ksensordev *sensdev)
@@ -176,100 +162,98 @@ sensor_find(int dev, enum sensor_type type, int numt)
 	return (NULL);
 }
 
-int
+struct sensor_task {
+	void				(*func)(void *);
+	void				*arg;
+
+	int				period;
+	struct timeout			timeout;
+	volatile enum {
+		ST_TICKING,
+		ST_WORKQ,
+		ST_RUNNING,
+		ST_DYING,
+		ST_DEAD
+	}				state;
+};
+
+void	sensor_task_tick(void *);
+void	sensor_task_work(void *, void *);
+
+struct sensor_task *
 sensor_task_register(void *arg, void (*func)(void *), int period)
 {
-	struct sensor_task	*st;
+	struct sensor_task *st;
 
 	st = malloc(sizeof(struct sensor_task), M_DEVBUF, M_NOWAIT);
 	if (st == NULL)
-		return (1);
+		return (NULL);
 
-	st->arg = arg;
 	st->func = func;
+	st->arg = arg;
 	st->period = period;
+	timeout_set(&st->timeout, sensor_task_tick, st);
 
-	st->running = 1;
+	sensor_task_tick(st);
 
-	if (TAILQ_EMPTY(&tasklist))
-		kthread_create_deferred(sensor_task_create, NULL);
-
-	st->nextrun = 0;
-	TAILQ_INSERT_HEAD(&tasklist, st, entry);
-	wakeup(&tasklist);
-
-	return (0);
+	return (st);
 }
 
 void
-sensor_task_unregister(void *arg)
+sensor_task_unregister(struct sensor_task *st)
 {
-	struct sensor_task	*st;
-
-	TAILQ_FOREACH(st, &tasklist, entry) {
-		if (st->arg == arg)
-			st->running = 0;
+	timeout_del(&st->timeout);
+
+	switch (st->state) {
+	case ST_TICKING:
+		free(st, M_DEVBUF);
+		break;
+
+	case ST_WORKQ:
+		st->state = ST_DYING;
+		break;
+
+	case ST_RUNNING:
+		st->state = ST_DYING;
+		while (st->state != ST_DEAD)
+			tsleep(st, 0, "stunr", 0);
+		break;
+	default:
+		panic("sensor_task_unregister: unexpected state %d",
+		    st->state);
 	}
 }
 
 void
-sensor_task_create(void *arg)
-{
-	if (kthread_create(sensor_task_thread, NULL, NULL, "sensors") != 0)
-		panic("sensors kthread");
-}
-
-void
-sensor_task_thread(void *arg)
+sensor_task_tick(void *arg)
 {
-	struct sensor_task	*st, *nst;
-	time_t			now;
-
-	while (!TAILQ_EMPTY(&tasklist)) {
-		while ((nst = TAILQ_FIRST(&tasklist))->nextrun >
-		    (now = time_uptime))
-			tsleep(&tasklist, PWAIT, "timeout",
-			    (nst->nextrun - now) * hz);
+	struct sensor_task	*st = arg;
 
-		while ((st = nst) != NULL) {
-			nst = TAILQ_NEXT(st, entry);
-
-			if (st->nextrun > now)
-				break;
+	/* try to schedule the task */
+	if (workq_add_task(NULL, 0, sensor_task_work, st, NULL) != 0)
+		timeout_add(&st->timeout, hz/2);
 
-			/* take it out while we work on it */
-			TAILQ_REMOVE(&tasklist, st, entry);
-
-			if (!st->running) {
-				free(st, M_DEVBUF);
-				continue;
-			}
-
-			/* run the task */
-			st->func(st->arg);
-			/* stick it back in the tasklist */
-			sensor_task_schedule(st);
-		}
-	}
-
-	kthread_exit(0);
+	st->state = ST_WORKQ;
 }
 
 void
-sensor_task_schedule(struct sensor_task *st)
+sensor_task_work(void *xst, void *arg)
 {
-	struct sensor_task 	*cst;
-
-	st->nextrun = time_uptime + st->period;
+	struct sensor_task *st = xst;
 
-	TAILQ_FOREACH(cst, &tasklist, entry) {
-		if (cst->nextrun > st->nextrun) {
-			TAILQ_INSERT_BEFORE(cst, st, entry);
-			return;
-		}
+	if (st->state == ST_DYING) {
+		free(st, M_DEVBUF);
+		return;
 	}
 
-	/* must be an empty list, or at the end of the list */
-	TAILQ_INSERT_TAIL(&tasklist, st, entry);
-}
+	st->state = ST_RUNNING;
+	st->func(st->arg);
 
+	if (st->state == ST_DYING) {
+		st->state = ST_DEAD;
+		wakeup(st);
+	} else {
+		st->state = ST_TICKING;
+		timeout_add(&st->timeout, hz * st->period);
+	}
+}
diff --git a/sys/scsi/safte.c b/sys/scsi/safte.c
index db16edebfa2..df0464e5205 100644
--- a/sys/scsi/safte.c
+++ b/sys/scsi/safte.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: safte.c,v 1.36 2007/06/01 22:58:50 cnst Exp $ */
+/*	$OpenBSD: safte.c,v 1.37 2007/06/24 05:34:35 dlg Exp $ */
 
 /*
  * Copyright (c) 2005 David Gwynne <dlg@openbsd.org>
@@ -72,6 +72,7 @@ struct safte_softc {
 	int			sc_nsensors;
 	struct safte_sensor	*sc_sensors;
 	struct ksensordev	sc_sensordev;
+	struct sensor_task	*sc_sensortask;
 
 	int			sc_celsius;
 	int			sc_ntemps;
@@ -180,16 +181,20 @@ safte_attach(struct device *parent, struct device *self, void *aux)
 		return;
 	}
 
-	if (sc->sc_nsensors > 0 &&
-	    sensor_task_register(sc, safte_read_encstat, 10) != 0) {
-		printf("%s: unable to register update task\n", DEVNAME(sc));
-		sc->sc_nsensors = sc->sc_ntemps = 0;
-		free(sc->sc_sensors, M_DEVBUF);
-	} else {
-		for (i = 0; i < sc->sc_nsensors; i++)
-			sensor_attach(&sc->sc_sensordev, 
-			    &sc->sc_sensors[i].se_sensor);
-		sensordev_install(&sc->sc_sensordev);
+	if (sc->sc_nsensors > 0) {
+		sc->sc_sensortask = sensor_task_register(sc,
+		    safte_read_encstat, 10);
+		if (sc->sc_sensortask == NULL) {
+			printf("%s: unable to register update task\n",
+			    DEVNAME(sc));
+			sc->sc_nsensors = sc->sc_ntemps = 0;
+			free(sc->sc_sensors, M_DEVBUF);
+		} else {
+			for (i = 0; i < sc->sc_nsensors; i++)
+				sensor_attach(&sc->sc_sensordev, 
+				    &sc->sc_sensors[i].se_sensor);
+			sensordev_install(&sc->sc_sensordev);
+		}
 	}
 
 #if NBIO > 0
@@ -224,7 +229,7 @@ safte_detach(struct device *self, int flags)
 
 	if (sc->sc_nsensors > 0) {
 		sensordev_deinstall(&sc->sc_sensordev);
-		sensor_task_unregister(sc);
+		sensor_task_unregister(sc->sc_sensortask);
 
 		for (i = 0; i < sc->sc_nsensors; i++)
 			sensor_detach(&sc->sc_sensordev, 
diff --git a/sys/scsi/ses.c b/sys/scsi/ses.c
index d3d0d8650be..1af264912fe 100644
--- a/sys/scsi/ses.c
+++ b/sys/scsi/ses.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ses.c,v 1.44 2007/05/04 23:44:37 krw Exp $ */
+/*	$OpenBSD: ses.c,v 1.45 2007/06/24 05:34:35 dlg Exp $ */
 
 /*
  * Copyright (c) 2005 David Gwynne <dlg@openbsd.org>
@@ -84,6 +84,7 @@ struct ses_softc {
 #endif
 	TAILQ_HEAD(, ses_sensor) sc_sensors;
 	struct ksensordev	sc_sensordev;
+	struct sensor_task	*sc_sensortask;
 };
 
 struct cfattach ses_ca = {
@@ -169,18 +170,24 @@ ses_attach(struct device *parent, struct device *self, void *aux)
 		return;
 	}
 
-	if (!TAILQ_EMPTY(&sc->sc_sensors) &&
-	    sensor_task_register(sc, ses_refresh_sensors, 10) != 0) {
-		printf("%s: unable to register update task\n", DEVNAME(sc));
-		while (!TAILQ_EMPTY(&sc->sc_sensors)) {
-			sensor = TAILQ_FIRST(&sc->sc_sensors);
-			TAILQ_REMOVE(&sc->sc_sensors, sensor, se_entry);
-			free(sensor, M_DEVBUF);
+	if (!TAILQ_EMPTY(&sc->sc_sensors)) {
+		sc->sc_sensortask = sensor_task_register(sc,
+		    ses_refresh_sensors, 10);
+		if (sc->sc_sensortask == NULL) {
+			printf("%s: unable to register update task\n",
+			    DEVNAME(sc));
+			while (!TAILQ_EMPTY(&sc->sc_sensors)) {
+				sensor = TAILQ_FIRST(&sc->sc_sensors);
+				TAILQ_REMOVE(&sc->sc_sensors, sensor,
+				    se_entry);
+				free(sensor, M_DEVBUF);
+			}
+		} else {
+			TAILQ_FOREACH(sensor, &sc->sc_sensors, se_entry)
+				sensor_attach(&sc->sc_sensordev,
+				    &sensor->se_sensor);
+			sensordev_install(&sc->sc_sensordev);
 		}
-	} else {
-		TAILQ_FOREACH(sensor, &sc->sc_sensors, se_entry)
-			sensor_attach(&sc->sc_sensordev, &sensor->se_sensor);
-		sensordev_install(&sc->sc_sensordev);
 	}
 
 #if NBIO > 0
@@ -229,7 +236,7 @@ ses_detach(struct device *self, int flags)
 
 	if (!TAILQ_EMPTY(&sc->sc_sensors)) {
 		sensordev_deinstall(&sc->sc_sensordev);
-		sensor_task_unregister(sc);
+		sensor_task_unregister(sc->sc_sensortask);
 
 		while (!TAILQ_EMPTY(&sc->sc_sensors)) {
 			sensor = TAILQ_FIRST(&sc->sc_sensors);
diff --git a/sys/sys/sensors.h b/sys/sys/sensors.h
index 411027ecaa2..94fb67c640b 100644
--- a/sys/sys/sensors.h
+++ b/sys/sys/sensors.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sensors.h,v 1.23 2007/03/22 16:55:31 deraadt Exp $	*/
+/*	$OpenBSD: sensors.h,v 1.24 2007/06/24 05:34:35 dlg Exp $	*/
 
 /*
  * Copyright (c) 2003, 2004 Alexander Yurchenko <grange@openbsd.org>
@@ -153,8 +153,9 @@ void			 sensor_detach(struct ksensordev *, struct ksensor *);
 struct ksensor		*sensor_find(int, enum sensor_type, int);
 
 /* task scheduling */
-int		sensor_task_register(void *, void (*)(void *), int);
-void		sensor_task_unregister(void *);
+struct sensor_task;
+struct sensor_task	*sensor_task_register(void *, void (*)(void *), int);
+void			 sensor_task_unregister(struct sensor_task *);
 
 #endif	/* _KERNEL */