diff mbox

[Resend] ACPI / EC: Remove race between EC driver and suspend process (rev. 3)

Message ID 201003082210.56660.rjw@sisk.pl (mailing list archive)
State New, archived
Headers show

Commit Message

Rafael Wysocki March 8, 2010, 9:10 p.m. UTC
None
diff mbox

Patch

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_BLOCKED,		/* Transactions are blocked */
 };
 
 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
@@ -291,6 +292,10 @@  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_BLOCKED, &ec->flags)) {
+		status = -EINVAL;
+		goto unlock;
+	}
 	if (ec->global_lock) {
 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 		if (ACPI_FAILURE(status)) {
@@ -453,6 +458,32 @@  int ec_transaction(u8 command,
 
 EXPORT_SYMBOL(ec_transaction);
 
+void acpi_ec_block_transactions(void)
+{
+	struct acpi_ec *ec = first_ec;
+
+	if (!ec)
+		return;
+
+	mutex_lock(&ec->lock);
+	/* Prevent transactions from being carried out */
+	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
+	mutex_unlock(&ec->lock);
+}
+
+void acpi_ec_unblock_transactions(void)
+{
+	struct acpi_ec *ec = first_ec;
+
+	if (!ec)
+		return;
+
+	mutex_lock(&ec->lock);
+	/* Allow transactions to be carried out again */
+	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
+	mutex_unlock(&ec->lock);
+}
+
 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_block_transactions(void);
+void acpi_ec_unblock_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
@@ -552,8 +552,17 @@  static void acpi_hibernation_leave(void)
 	hibernate_nvs_restore();
 }
 
-static void acpi_pm_enable_gpes(void)
+static int acpi_pm_pre_restore(void)
 {
+	acpi_disable_all_gpes();
+	acpi_os_wait_events_complete(NULL);
+	acpi_ec_block_transactions();
+	return 0;
+}
+
+static void acpi_pm_restore_cleanup(void)
+{
+	acpi_ec_unblock_transactions();
 	acpi_enable_all_runtime_gpes();
 }
 
@@ -565,8 +574,8 @@  static struct platform_hibernation_ops a
 	.prepare = acpi_pm_prepare,
 	.enter = acpi_hibernation_enter,
 	.leave = acpi_hibernation_leave,
-	.pre_restore = acpi_pm_disable_gpes,
-	.restore_cleanup = acpi_pm_enable_gpes,
+	.pre_restore = acpi_pm_pre_restore,
+	.restore_cleanup = acpi_pm_restore_cleanup,
 };
 
 /**
@@ -618,8 +627,8 @@  static struct platform_hibernation_ops a
 	.prepare = acpi_pm_disable_gpes,
 	.enter = acpi_hibernation_enter,
 	.leave = acpi_hibernation_leave,
-	.pre_restore = acpi_pm_disable_gpes,
-	.restore_cleanup = acpi_pm_enable_gpes,
+	.pre_restore = acpi_pm_pre_restore,
+	.restore_cleanup = acpi_pm_restore_cleanup,
 	.recover = acpi_pm_finish,
 };
 #endif /* CONFIG_HIBERNATION */