* fix bst.status. We mark some bits, but forgot to reset all of them

  before.  The symptom is that the battery inform us its charge and discharge
  at the same time...

* fix bst.rate to correctly output the (dis)charging rate.  We'll use
  the current average over one minute command and not the at_rate command.
  Note that this method is not correct if the capacity_mode is set, but
  since we don't set it ourself, it is not a problem.

  The at_rate do not give the actual rate but is used to compute the
  estimated time for (dis)charging a battery.  We should actually
  write an estimation of the actual rate using at_rate cmd and then
  perform a read to the various estimators.

Approved by:	njl
MFC after:	2 days

sys/dev/acpica/acpi_smbat.c

@@ -341,27 +341,28 @@ acpi_smbat_get_bst(device_t dev, struct acpi_bst *bst)
 	if (acpi_smbus_read_2(sc, addr, SMBATT_CMD_BATTERY_STATUS, &val))
 		goto out;
 
-	if (val & SMBATT_BS_DISCHARGING) {
+	sc->bst.state = 0;
+	if (val & SMBATT_BS_DISCHARGING)
 		sc->bst.state |= ACPI_BATT_STAT_DISCHARG;
 
-		/*
-		 * If the rate is negative, it is discharging.  Otherwise,
-		 * it is charging.
-		 */
-		if (acpi_smbus_read_2(sc, addr, SMBATT_CMD_AT_RATE, &val))
-			goto out;
-		if (val < 0)
-			sc->bst.rate = (-val) * factor;
-		else
-			sc->bst.rate = -1;
-	} else {
-		sc->bst.state |= ACPI_BATT_STAT_CHARGING;
-		sc->bst.rate = -1;
-	}
-
 	if (val & SMBATT_BS_REMAINING_CAPACITY_ALARM)
 		sc->bst.state |= ACPI_BATT_STAT_CRITICAL;
 
+	/*
+	 * If the rate is negative, it is discharging.  Otherwise,
+	 * it is charging.
+	 */
+	if (acpi_smbus_read_2(sc, addr, SMBATT_CMD_CURRENT, &val))
+		goto out;
+
+	if (val > 0) {
+		sc->bst.rate = val * factor;
+		sc->bst.state |= ACPI_BATT_STAT_CHARGING;
+	} else if (val < 0)
+		sc->bst.rate = (-val) * factor;
+	else
+		sc->bst.rate = 0;
+
 	if (acpi_smbus_read_2(sc, addr, SMBATT_CMD_REMAINING_CAPACITY, &val))
 		goto out;
 	sc->bst.cap = val * factor;