If a machine has no _LIDs, then none can be open. This diff fixes a problem

where machines without any _LIDs were going back to sleep after hibernate
due to the recent suspend-if-lid-closed-on-resume diff. Noticed on qemu,
which doesn't have any _LIDs.

discussed with deraadt

3 files changed, 27 insertions, 16 deletions

diff --git a/sys/dev/acpi/acpi.c b/sys/dev/acpi/acpi.c
index 37b092787de..67659c875cf 100644
--- a/sys/dev/acpi/acpi.c
+++ b/sys/dev/acpi/acpi.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: acpi.c,v 1.274 2014/11/18 23:55:01 krw Exp $ */
+/* $OpenBSD: acpi.c,v 1.275 2014/11/23 20:33:47 mlarkin Exp $ */
 /*
  * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
  * Copyright (c) 2005 Jordan Hargrave <jordan@openbsd.org>
@@ -2251,10 +2251,8 @@ fail_alloc:
 	acpi_record_event(sc, APM_NORMAL_RESUME);
 	acpi_indicator(sc, ACPI_SST_WORKING);
 
-	/*
-	 * If we woke up but the lid is closed, go back to sleep
-	 */
-	if (!acpibtn_checklidopen())
+	/* If we woke up but all the lids are closed, go back to sleep */
+	if (acpibtn_numopenlids() == 0)
 		acpi_addtask(sc, acpi_sleep_task, sc, state);
 
 fail_tts:
diff --git a/sys/dev/acpi/acpibtn.c b/sys/dev/acpi/acpibtn.c
index 4cc98402600..391558ded0d 100644
--- a/sys/dev/acpi/acpibtn.c
+++ b/sys/dev/acpi/acpibtn.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: acpibtn.c,v 1.38 2014/11/08 07:45:10 mlarkin Exp $ */
+/* $OpenBSD: acpibtn.c,v 1.39 2014/11/23 20:33:47 mlarkin Exp $ */
 /*
  * Copyright (c) 2005 Marco Peereboom <marco@openbsd.org>
  *
@@ -75,23 +75,36 @@ struct cfdriver acpibtn_cd = {
 
 const char *acpibtn_hids[] = { ACPI_DEV_LD, ACPI_DEV_PBD, ACPI_DEV_SBD, 0 };
 
+/*
+ * acpibtn_numopenlids
+ *
+ * Return the number of _LID devices that are in the "open" state. Used to
+ * determine if we should go back to sleep/hibernate if we woke up with the all
+ * the lids still closed for some reason. If the machine has no lids, returns
+ * -1.
+ */
 int
-acpibtn_checklidopen(void)
+acpibtn_numopenlids(void)
 {
-	int64_t val, status;
+	int64_t val, ct;
 	struct acpi_lid *lid;
 
-	status = 0;
+	/* If we have no lids ... */
+	if (SLIST_EMPTY(&acpibtn_lids))
+		return (-1);
 
-	/* Check if any of the lid(s) are open */
+	ct = 0;
+
+	/*
+	 * Determine how many lids are open. Assumes _LID evals to 1 or 0, for
+	 * on / off (which is what the spec says).
+	 */
 	SLIST_FOREACH(lid, &acpibtn_lids, abl_link)
 		if (!aml_evalinteger(lid->abl_softc->sc_acpi,
 		    lid->abl_softc->sc_devnode, "_LID", 0, NULL, &val))
-			status |= val;
-		else
-			return (0);
+			ct += val;
 
-	return (status);
+	return (ct);
 }
 
 int
diff --git a/sys/dev/acpi/acpidev.h b/sys/dev/acpi/acpidev.h
index c007aa94eae..f8cdfbb4919 100644
--- a/sys/dev/acpi/acpidev.h
+++ b/sys/dev/acpi/acpidev.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: acpidev.h,v 1.35 2014/11/08 07:45:10 mlarkin Exp $ */
+/* $OpenBSD: acpidev.h,v 1.36 2014/11/23 20:33:47 mlarkin Exp $ */
 /*
  * Copyright (c) 2005 Marco Peereboom <marco@openbsd.org>
  * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
@@ -337,5 +337,5 @@ struct acpiec_softc {
 
 void		acpibtn_disable_psw(void);
 void		acpibtn_enable_psw(void);
-int		acpibtn_checklidopen(void);
+int		acpibtn_numopenlids(void);
 #endif /* __DEV_ACPI_ACPIDEV_H__ */