There is a race between resume from hibernation and the EC driver
that may result in restoring the hibernation image in the middle of
an EC transaction in progress, which in turn may lead to
unpredictable behavior of the platform.
To remove that race condition, add a helpers for suspending and
resuming EC transactions in a safe way to be executed by the ACPI
platform hibernate pre-restore and restore cleanup callbacks.
http://bugzilla.kernel.org/show_bug.cgi?id=14668
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
enum {
EC_FLAGS_QUERY_PENDING, /* Query is pending */
EC_FLAGS_GPE_STORM, /* GPE storm detected */
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
+ EC_FLAGS_FROZEN, /* Transactions are suspended */
};
/* If we find an EC via the ECDT, we need to keep a ptr to its context */
};
/* If we find an EC via the ECDT, we need to keep a ptr to its context */
if (t->rdata)
memset(t->rdata, 0, t->rlen);
mutex_lock(&ec->lock);
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)) {
if (ec->global_lock) {
status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
if (ACPI_FAILURE(status)) {
EXPORT_SYMBOL(ec_transaction);
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;
static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
{
int result;
int acpi_ec_init(void);
int acpi_ec_ecdt_probe(void);
int acpi_boot_ec_enable(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
/*--------------------------------------------------------------------------
Suspend/Resume
hibernate_nvs_restore();
}
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_suspend_transactions();
+ return 0;
+}
+
+static void acpi_pm_restore_cleanup(void)
+{
+ acpi_ec_resume_transactions();
acpi_enable_all_runtime_gpes();
}
acpi_enable_all_runtime_gpes();
}
.prepare = acpi_pm_prepare,
.enter = acpi_hibernation_enter,
.leave = acpi_hibernation_leave,
.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,
.prepare = acpi_pm_disable_gpes,
.enter = acpi_hibernation_enter,
.leave = acpi_hibernation_leave,
.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 */
.recover = acpi_pm_finish,
};
#endif /* CONFIG_HIBERNATION */