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path: root/drivers/acpi/ec.c
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Diffstat (limited to 'drivers/acpi/ec.c')
-rw-r--r--drivers/acpi/ec.c69
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) {