for every sensor esm looks after it has to talk to the hardware, which

means it could busy wait while the hardware gets ready. all the sensors
are updated out of a single timeout. doing this for the 30ish esm sensors
on my machine is probably not a good thing...

this changes the way updates are handled. instead of a single big update
for all the sensors, we now update only one sensor in a timeout. after
that sensor has been updated it sets up a very short timeout for the next
sensor to run out of. we also use the short timeouts to retry the same
sensor if the hardware isnt ready which means we avoid the (worst) busy
wait.

1 files changed, 26 insertions, 13 deletions

diff --git a/sys/arch/i386/i386/esm.c b/sys/arch/i386/i386/esm.c
index 9969db4dee8..a4cd31eb1fb 100644
--- a/sys/arch/i386/i386/esm.c
+++ b/sys/arch/i386/i386/esm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: esm.c,v 1.6 2005/11/22 08:33:24 dlg Exp $ */
+/*	$OpenBSD: esm.c,v 1.7 2005/11/22 11:54:53 dlg Exp $ */
 
 /*
  * Copyright (c) 2005 Jordan Hargrave <jordan@openbsd.org>
@@ -73,6 +73,8 @@ struct esm_softc {
 	bus_space_handle_t	sc_ioh;
 
 	TAILQ_HEAD(, esm_sensor) sc_sensors;
+	struct esm_sensor	*sc_nextsensor;
+	int			sc_retries;
 	struct timeout		sc_timeout;
 };
 
@@ -168,6 +170,8 @@ esm_attach(struct device *parent, struct device *self, void *aux)
 
 	if (!TAILQ_EMPTY(&sc->sc_sensors)) {
 		DPRINTF("%s: starting refresh\n", DEVNAME(sc));
+		sc->sc_nextsensor = TAILQ_FIRST(&sc->sc_sensors);
+		sc->sc_retries = 0;
 		timeout_set(&sc->sc_timeout, esm_refresh, sc);
 		timeout_add(&sc->sc_timeout, hz * 10);
 	}
@@ -177,26 +181,24 @@ void
 esm_refresh(void *arg)
 {
 	struct esm_softc	*sc = arg;
-	struct esm_sensor	*sensor;
+	struct esm_sensor	*sensor = sc->sc_nextsensor;
 	struct esm_smb_req	req;
 	struct esm_smb_resp	resp;
 	struct esm_smb_resp_val	*val = &resp.resp_val;
 
 	memset(&req, 0, sizeof(req));
 	req.h_cmd = ESM2_CMD_SMB_XMIT_RECV;
+	req.h_dev = sensor->es_dev;
 	req.h_txlen = sizeof(req.req_val);
 	req.h_rxlen = sizeof(resp.resp_val);
 	req.req_val.v_cmd = ESM2_SMB_SENSOR_VALUE;
+	req.req_val.v_sensor = sensor->es_id;
 
-	TAILQ_FOREACH(sensor, &sc->sc_sensors, es_entry) {
-		req.h_dev = sensor->es_dev;
-		req.req_val.v_sensor = sensor->es_id;
-
-		if (esm_smb_cmd(sc, &req, &resp, 1) != 0) {
-			sensor->es_sensor.flags |= SENSOR_FINVALID;
-			continue;
-		}
-
+	if (esm_smb_cmd(sc, &req, &resp, 0) != 0) {
+		if (++sc->sc_retries < 10)
+			goto tick;
+		sensor->es_sensor.flags |= SENSOR_FINVALID;
+	} else {
 		switch (sensor->es_sensor.type) {
 		case SENSOR_TEMP:
 			sensor->es_sensor.value = esm_val2temp(val->v_reading);
@@ -208,9 +210,20 @@ esm_refresh(void *arg)
 			sensor->es_sensor.value = val->v_reading;
 			break;
 		}
+		sensor->es_sensor.flags &= ~SENSOR_FINVALID;
 	}
 
-	timeout_add(&sc->sc_timeout, hz * 10);
+	sc->sc_nextsensor = TAILQ_NEXT(sensor, es_entry);
+	sc->sc_retries = 0;
+
+	if (sc->sc_nextsensor == NULL) {
+		sc->sc_nextsensor = TAILQ_FIRST(&sc->sc_sensors);
+		timeout_add(&sc->sc_timeout, hz * 10);
+		return;
+	}
+tick:
+	timeout_add(&sc->sc_timeout, hz / 100);
+	
 }
 
 int
@@ -545,7 +558,7 @@ esm_cmd(struct esm_softc *sc, void *cmd, size_t cmdlen, void *resp,
 	int			i;
 
 	/* Wait for card ready */
-	if (esm_bmc_ready(sc, ESM2_TC_REG, ESM2_TC_READY, 0, 1) != 0)
+	if (esm_bmc_ready(sc, ESM2_TC_REG, ESM2_TC_READY, 0, wait) != 0)
 		return (1); /* busy */
 
 	/* Write command data to port */