CVS commit: src/sys/dev/acpi

[Jukka Ruohonen]

Module Name:    src
Committed By:   jruoho
Date:           Fri Jun  3 18:50:36 UTC 2011

Modified Files:
        src/sys/dev/acpi: acpi_pmtr.c

Log Message:
Add locking to account improbable but possible race between the notify
handler and sysmon_envsys(9)'s refresh routine.


To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/sys/dev/acpi/acpi_pmtr.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/dev/acpi/acpi_pmtr.c
diff -u src/sys/dev/acpi/acpi_pmtr.c:1.3 src/sys/dev/acpi/acpi_pmtr.c:1.4
--- src/sys/dev/acpi/acpi_pmtr.c:1.3	Wed Feb 16 09:05:12 2011
+++ src/sys/dev/acpi/acpi_pmtr.c	Fri Jun  3 18:50:36 2011
@@ -1,4 +1,4 @@
-/*	$NetBSD: acpi_pmtr.c,v 1.3 2011/02/16 09:05:12 jruoho Exp $ */
+/*	$NetBSD: acpi_pmtr.c,v 1.4 2011/06/03 18:50:36 jruoho Exp $ */
 
 /*-
  * Copyright (c) 2011 Jukka Ruohonen <jruoho...@iki.fi>
@@ -27,10 +27,11 @@
  * SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_pmtr.c,v 1.3 2011/02/16 09:05:12 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_pmtr.c,v 1.4 2011/06/03 18:50:36 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/module.h>
+#include <sys/mutex.h>
 
 #include <dev/acpi/acpireg.h>
 #include <dev/acpi/acpivar.h>
@@ -79,6 +80,7 @@
 	envsys_data_t		 sc_sensor_o;
 	uint32_t		 sc_cap[ACPIPMTR_CAP_COUNT];
 	int32_t			 sc_interval;
+	kmutex_t		 sc_mtx;
 };
 
 const char * const acpi_pmtr_ids[] = {
@@ -128,6 +130,7 @@
 	aprint_normal(": ACPI Power Meter\n");
 
 	(void)pmf_device_register(self, NULL, NULL);
+	mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE);
 
 	if (acpipmtr_cap_get(self, true) != true)
 		return;
@@ -162,6 +165,8 @@
 	if (sc->sc_sme != NULL)
 		sysmon_envsys_unregister(sc->sc_sme);
 
+	mutex_destroy(&sc->sc_mtx);
+
 	return 0;
 }
 
@@ -369,6 +374,8 @@
 {
 	struct acpipmtr_softc *sc = device_private(self);
 
+	mutex_enter(&sc->sc_mtx);
+
 	switch (sc->sc_cap[ACPIPMTR_CAP_TYPE]) {
 
 	case ACPIPMTR_POWER_INPUT:
@@ -386,6 +393,8 @@
 		sc->sc_sensor_o.state = ENVSYS_SINVALID;
 		break;
 	}
+
+	mutex_exit(&sc->sc_mtx);
 }
 
 static int32_t
@@ -462,8 +471,14 @@
 
 	case ACPIPMTR_NOTIFY_CAP:
 
-		if (acpipmtr_cap_get(self, false) != true)
+		mutex_enter(&sc->sc_mtx);
+
+		if (acpipmtr_cap_get(self, false) != true) {
+			mutex_exit(&sc->sc_mtx);
 			break;
+		}
+
+		mutex_exit(&sc->sc_mtx);
 
 		acpipmtr_sensor_type(self);
 		break;