1 files changed, 42 insertions, 27 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index d7a6bbbb834..f2234db85da 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -39,6 +39,7 @@
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
+#include <linux/slab.h>
 #include <asm/io.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
@@ -76,8 +77,9 @@ 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 +293,10 @@ 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 +459,32 @@ 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;
@@ -597,12 +629,12 @@ static u32 acpi_ec_gpe_handler(void *data)
 
 static acpi_status
 acpi_ec_space_handler(u32 function, acpi_physical_address address,
-		      u32 bits, u64 *value,
+		      u32 bits, u64 *value64,
 		      void *handler_context, void *region_context)
 {
 	struct acpi_ec *ec = handler_context;
-	int result = 0, i;
-	u8 temp = 0;
+	int result = 0, i, bytes = bits / 8;
+	u8 *value = (u8 *)value64;
 
 	if ((address > 0xFF) || !value || !handler_context)
 		return AE_BAD_PARAMETER;
@@ -610,32 +642,15 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
 	if (function != ACPI_READ && function != ACPI_WRITE)
 		return AE_BAD_PARAMETER;
 
-	if (bits != 8 && acpi_strict)
-		return AE_BAD_PARAMETER;
-
-	if (EC_FLAGS_MSI)
+	if (EC_FLAGS_MSI || bits > 8)
 		acpi_ec_burst_enable(ec);
 
-	if (function == ACPI_READ) {
-		result = acpi_ec_read(ec, address, &temp);
-		*value = temp;
-	} else {
-		temp = 0xff & (*value);
-		result = acpi_ec_write(ec, address, temp);
-	}
+	for (i = 0; i < bytes; ++i, ++address, ++value)
+		result = (function == ACPI_READ) ?
+			acpi_ec_read(ec, address, value) :
+			acpi_ec_write(ec, address, *value);
 
-	for (i = 8; unlikely(bits - i > 0); i += 8) {
-		++address;
-		if (function == ACPI_READ) {
-			result = acpi_ec_read(ec, address, &temp);
-			(*value) |= ((u64)temp) << i;
-		} else {
-			temp = 0xff & ((*value) >> i);
-			result = acpi_ec_write(ec, address, temp);
-		}
-	}
-
-	if (EC_FLAGS_MSI)
+	if (EC_FLAGS_MSI || bits > 8)
 		acpi_ec_burst_disable(ec);
 
 	switch (result) {