[PATCH 3/3] cros_ec: Don't signal wake event for non-wake host events

From: Thierry Escande
Date: Wed Jan 25 2017 - 12:01:41 EST


From: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>

The subset of wake-enabled host events is defined by the EC, but the EC
may still send non-wake host events if we're in the process of
suspending. Get the mask of wake-enabled host events from the EC and
filter out non-wake events to prevent spurious aborted suspend
attempts.

Signed-off-by: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>
Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxxxxx>
---
drivers/mfd/cros_ec.c | 14 ++++++--
drivers/platform/chrome/cros_ec_proto.c | 60 +++++++++++++++++++++++++++++++++
include/linux/mfd/cros_ec.h | 12 +++++++
3 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index abd8342..510dfbb 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -53,12 +53,22 @@ static const struct mfd_cell ec_pd_cell = {
static irqreturn_t ec_irq_thread(int irq, void *data)
{
struct cros_ec_device *ec_dev = data;
+ u8 wake_event = 1;
+ u32 host_event;
int ret;

- if (device_may_wakeup(ec_dev->dev))
+ ret = cros_ec_get_next_event(ec_dev);
+
+ if (ret > 0 && ec_dev->mkbp_event_supported) {
+ /* Don't signal wake event for non-wake host events */
+ host_event = cros_ec_get_host_event(ec_dev);
+ if (host_event && !(host_event & ec_dev->host_event_wake_mask))
+ wake_event = 0;
+ }
+
+ if (wake_event && device_may_wakeup(ec_dev->dev))
pm_wakeup_event(ec_dev->dev, 0);

- ret = cros_ec_get_next_event(ec_dev);
if (ret > 0)
blocking_notifier_call_chain(&ec_dev->event_notifier,
0, ec_dev);
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 256249b..a216a32 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -150,6 +150,40 @@ int cros_ec_check_result(struct cros_ec_device *ec_dev,
}
EXPORT_SYMBOL(cros_ec_check_result);

+/*
+ * cros_ec_get_host_event_wake_mask
+ *
+ * Get the mask of host events that cause wake from suspend.
+ *
+ * @ec_dev: EC device to call
+ * @msg: message structure to use
+ * @mask: result when function returns >=0.
+ *
+ * LOCKING:
+ * the caller has ec_dev->lock mutex, or the caller knows there is
+ * no other command in progress.
+ */
+static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg,
+ uint32_t *mask)
+{
+ struct ec_response_host_event_mask *r;
+ int ret;
+
+ msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
+ msg->version = 0;
+ msg->outsize = 0;
+ msg->insize = sizeof(*r);
+
+ ret = send_command(ec_dev, msg);
+ if (ret > 0) {
+ r = (struct ec_response_host_event_mask *)msg->data;
+ *mask = r->mask;
+ }
+
+ return ret;
+}
+
static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
int devidx,
struct cros_ec_command *msg)
@@ -387,6 +421,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
else
ec_dev->mkbp_event_supported = 1;

+ /*
+ * Get host event wake mask, assume all events are wake events
+ * if unavailable.
+ */
+ ret = cros_ec_get_host_event_wake_mask(ec_dev, proto_msg,
+ &ec_dev->host_event_wake_mask);
+ if (ret < 0)
+ ec_dev->host_event_wake_mask = U32_MAX;
+
ret = 0;

exit:
@@ -507,3 +550,20 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev)
return get_keyboard_state_event(ec_dev);
}
EXPORT_SYMBOL(cros_ec_get_next_event);
+
+u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
+{
+ if (WARN_ON(!ec_dev->mkbp_event_supported))
+ return 0;
+
+ if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
+ return 0;
+
+ if (ec_dev->event_size != sizeof(u32)) {
+ dev_warn(ec_dev->dev, "Invalid host event size\n");
+ return 0;
+ }
+
+ return get_unaligned_le32(&ec_dev->event_data.data.host_event);
+}
+EXPORT_SYMBOL(cros_ec_get_host_event);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index f62043a..8f37c4e 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -146,6 +146,7 @@ struct cros_ec_device {

struct ec_response_get_next_event event_data;
int event_size;
+ u32 host_event_wake_mask;
};

/**
@@ -297,6 +298,17 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev);
*/
int cros_ec_get_next_event(struct cros_ec_device *ec_dev);

+/**
+ * cros_ec_get_host_event - Return a mask of event set by the EC.
+ *
+ * Once cros_ec_get_next_event() has been called, if the event source is
+ * a host event, this function returns the precise event that triggered
+ * the interrupt.
+ *
+ * This function is a helper to know which events are raised.
+ */
+u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
+
/* sysfs stuff */
extern struct attribute_group cros_ec_attr_group;
extern struct attribute_group cros_ec_lightbar_attr_group;
--
2.7.4