1 files changed, 32 insertions, 1 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index d7a6bbbb834c..1ac28c6a672e 100644
--- a/drivers/acpi/ec.c
+++ b/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_FROZEN,                /* Transactions are suspended */
 };
 
 /* 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 acpi_ec *ec, struct transaction *t)
         if (t->rdata)
                 memset(t->rdata, 0, t->rlen);
         mutex_lock(&ec->lock);
+        if (test_bit(EC_FLAGS_FROZEN, &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_suspend_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_FROZEN, &ec->flags);
+        mutex_unlock(&ec->lock);
+}
+
+void acpi_ec_resume_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_FROZEN, &ec->flags);
+        mutex_unlock(&ec->lock);
+}
+
 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 {
         int result;