Index: linux-2.6/drivers/acpi/ec.c
===================================================================
--- linux-2.6.orig/drivers/acpi/ec.c
+++ linux-2.6/drivers/acpi/ec.c
@@ -76,8 +76,9 @@ enum ec_command {
 enum {
 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
-	EC_FLAGS_HANDLERS_INSTALLED	/* Handlers for GPE and
+	EC_FLAGS_HANDLERS_INSTALLED,	/* Handlers for GPE and
 					 * OpReg are installed */
+	EC_FLAGS_SUSPENDED,		/* Driver is suspended */
 };
 
 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
@@ -291,6 +292,12 @@ static int acpi_ec_transaction(struct ac
 	if (t->rdata)
 		memset(t->rdata, 0, t->rlen);
 	mutex_lock(&ec->lock);
+	if (test_bit(EC_FLAGS_SUSPENDED, &ec->flags)) {
+		pr_err(PREFIX
+			"EC transaction discarded due to power transition\n");
+		status = -EINVAL;
+		goto unlock;
+	}
 	if (ec->global_lock) {
 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 		if (ACPI_FAILURE(status)) {
@@ -445,6 +452,29 @@ int ec_transaction(u8 command,
 
 EXPORT_SYMBOL(ec_transaction);
 
+void acpi_ec_suspend_transactions(void)
+{
+	struct acpi_ec *ec = first_ec;
+
+	if (!ec)
+		return;
+
+	mutex_lock(&ec->lock);
+	/* Prevent transactions from happening while suspended */
+	set_bit(EC_FLAGS_SUSPENDED, &ec->flags);
+	mutex_unlock(&ec->lock);
+}
+
+void acpi_ec_resume_transactions(void)
+{
+	/*
+	 * Allow transactions to happen again (this function is called from
+	 * atomic context during wake-up, so we don't need to acquire the mutex)
+	 */
+	if (first_ec)
+		clear_bit(EC_FLAGS_SUSPENDED, &first_ec->flags);
+}
+
 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 {
 	int result;
Index: linux-2.6/drivers/acpi/internal.h
===================================================================
--- linux-2.6.orig/drivers/acpi/internal.h
+++ linux-2.6/drivers/acpi/internal.h
@@ -49,6 +49,8 @@ void acpi_early_processor_set_pdc(void);
 int acpi_ec_init(void);
 int acpi_ec_ecdt_probe(void);
 int acpi_boot_ec_enable(void);
+void acpi_ec_suspend_transactions(void);
+void acpi_ec_resume_transactions(void);
 
 /*--------------------------------------------------------------------------
                                   Suspend/Resume
Index: linux-2.6/drivers/acpi/sleep.c
===================================================================
--- linux-2.6.orig/drivers/acpi/sleep.c
+++ linux-2.6/drivers/acpi/sleep.c
@@ -110,11 +110,12 @@ void __init acpi_old_suspend_ordering(vo
 }
 
 /**
- *	acpi_pm_disable_gpes - Disable the GPEs.
+ *	acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
  */
-static int acpi_pm_disable_gpes(void)
+static int acpi_pm_freeze(void)
 {
 	acpi_disable_all_gpes();
+	acpi_ec_suspend_transactions();
 	return 0;
 }
 
@@ -142,7 +143,8 @@ static int acpi_pm_prepare(void)
 	int error = __acpi_pm_prepare();
 
 	if (!error)
-		acpi_disable_all_gpes();
+		acpi_pm_freeze();
+
 	return error;
 }
 
@@ -276,6 +278,8 @@ static int acpi_suspend_enter(suspend_st
 	 */
 	acpi_disable_all_gpes();
 
+	acpi_ec_resume_transactions();
+
 	local_irq_restore(flags);
 	printk(KERN_DEBUG "Back to C!\n");
 
@@ -333,7 +337,7 @@ static int acpi_suspend_begin_old(suspen
 static struct platform_suspend_ops acpi_suspend_ops_old = {
 	.valid = acpi_suspend_state_valid,
 	.begin = acpi_suspend_begin_old,
-	.prepare_late = acpi_pm_disable_gpes,
+	.prepare_late = acpi_pm_freeze,
 	.enter = acpi_suspend_enter,
 	.wake = acpi_pm_finish,
 	.end = acpi_pm_end,
@@ -522,6 +526,7 @@ static int acpi_hibernation_enter(void)
 	status = acpi_enter_sleep_state(ACPI_STATE_S4);
 	/* Reprogram control registers and execute _BFS */
 	acpi_leave_sleep_state_prep(ACPI_STATE_S4);
+	acpi_ec_resume_transactions();
 	local_irq_restore(flags);
 
 	return ACPI_SUCCESS(status) ? 0 : -EFAULT;
@@ -550,6 +555,7 @@ static void acpi_hibernation_leave(void)
 	}
 	/* Restore the NVS memory area */
 	hibernate_nvs_restore();
+	acpi_ec_resume_transactions();
 }
 
 static void acpi_pm_enable_gpes(void)
@@ -565,7 +571,7 @@ static struct platform_hibernation_ops a
 	.prepare = acpi_pm_prepare,
 	.enter = acpi_hibernation_enter,
 	.leave = acpi_hibernation_leave,
-	.pre_restore = acpi_pm_disable_gpes,
+	.pre_restore = acpi_pm_freeze,
 	.restore_cleanup = acpi_pm_enable_gpes,
 };
 
@@ -598,12 +604,9 @@ static int acpi_hibernation_begin_old(vo
 
 static int acpi_hibernation_pre_snapshot_old(void)
 {
-	int error = acpi_pm_disable_gpes();
-
-	if (!error)
-		hibernate_nvs_save();
-
-	return error;
+	acpi_pm_freeze();
+	hibernate_nvs_save();
+	return 0;
 }
 
 /*
@@ -615,10 +618,10 @@ static struct platform_hibernation_ops a
 	.end = acpi_pm_end,
 	.pre_snapshot = acpi_hibernation_pre_snapshot_old,
 	.finish = acpi_hibernation_finish,
-	.prepare = acpi_pm_disable_gpes,
+	.prepare = acpi_pm_freeze,
 	.enter = acpi_hibernation_enter,
 	.leave = acpi_hibernation_leave,
-	.pre_restore = acpi_pm_disable_gpes,
+	.pre_restore = acpi_pm_freeze,
 	.restore_cleanup = acpi_pm_enable_gpes,
 	.recover = acpi_pm_finish,
 };
