Input: cyapa - fix for losing events during device power transitions

When changing the scan rate as part of runtime-resume process we may lose
some of the events, because:

1) for gen3 trackpads, the driver must msleep() some time to ensure that
the device is ready to accept next command;

2) for gen5 and later trackpads, the queue dumping function will simply
ignore the events when waiting for the set power mode command response.

The solution is to keep polling and report those valid events when the set
power mode command is in progress.

Signed-off-by: Dudley Du <dudl@cypress.com>
Tested-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 82 insertions, 17 deletions

diff --git a/drivers/input/mouse/cyapa_gen5.c b/drivers/input/mouse/cyapa_gen5.c
index 118ba977181e..5775d40b3d53 100644
--- a/drivers/input/mouse/cyapa_gen5.c
+++ b/drivers/input/mouse/cyapa_gen5.c
@@ -342,6 +342,9 @@ u8 pip_bl_read_app_info[] = { 0x04, 0x00, 0x0b, 0x00, 0x40, 0x00,
 static u8 cyapa_pip_bl_cmd_key[] = { 0xa5, 0x01, 0x02, 0x03,
 	0xff, 0xfe, 0xfd, 0x5a };
 
+static int cyapa_pip_event_process(struct cyapa *cyapa,
+				   struct cyapa_pip_report_data *report_data);
+
 int cyapa_pip_cmd_state_initialize(struct cyapa *cyapa)
 {
 	struct cyapa_pip_cmd_states *pip = &cyapa->cmd_states.pip;
@@ -350,6 +353,9 @@ int cyapa_pip_cmd_state_initialize(struct cyapa *cyapa)
 	atomic_set(&pip->cmd_issued, 0);
 	mutex_init(&pip->cmd_lock);
 
+	mutex_init(&pip->pm_stage_lock);
+	pip->pm_stage = CYAPA_PM_DEACTIVE;
+
 	pip->resp_sort_func = NULL;
 	pip->in_progress_cmd = PIP_INVALID_CMD;
 	pip->resp_data = NULL;
@@ -397,6 +403,38 @@ ssize_t cyapa_i2c_pip_write(struct cyapa *cyapa, u8 *buf, size_t size)
 	return 0;
 }
 
+static void cyapa_set_pip_pm_state(struct cyapa *cyapa,
+				   enum cyapa_pm_stage pm_stage)
+{
+	struct cyapa_pip_cmd_states *pip = &cyapa->cmd_states.pip;
+
+	mutex_lock(&pip->pm_stage_lock);
+	pip->pm_stage = pm_stage;
+	mutex_unlock(&pip->pm_stage_lock);
+}
+
+static void cyapa_reset_pip_pm_state(struct cyapa *cyapa)
+{
+	struct cyapa_pip_cmd_states *pip = &cyapa->cmd_states.pip;
+
+	/* Indicates the pip->pm_stage is not valid. */
+	mutex_lock(&pip->pm_stage_lock);
+	pip->pm_stage = CYAPA_PM_DEACTIVE;
+	mutex_unlock(&pip->pm_stage_lock);
+}
+
+static enum cyapa_pm_stage cyapa_get_pip_pm_state(struct cyapa *cyapa)
+{
+	struct cyapa_pip_cmd_states *pip = &cyapa->cmd_states.pip;
+	enum cyapa_pm_stage pm_stage;
+
+	mutex_lock(&pip->pm_stage_lock);
+	pm_stage = pip->pm_stage;
+	mutex_unlock(&pip->pm_stage_lock);
+
+	return pm_stage;
+}
+
 /**
  * This function is aimed to dump all not read data in Gen5 trackpad
  * before send any command, otherwise, the interrupt line will be blocked.
@@ -404,7 +442,9 @@ ssize_t cyapa_i2c_pip_write(struct cyapa *cyapa, u8 *buf, size_t size)
 int cyapa_empty_pip_output_data(struct cyapa *cyapa,
 		u8 *buf, int *len, cb_sort func)
 {
+	struct input_dev *input = cyapa->input;
 	struct cyapa_pip_cmd_states *pip = &cyapa->cmd_states.pip;
+	enum cyapa_pm_stage pm_stage = cyapa_get_pip_pm_state(cyapa);
 	int length;
 	int report_count;
 	int empty_count;
@@ -478,6 +518,12 @@ int cyapa_empty_pip_output_data(struct cyapa *cyapa,
 			*len = length;
 			/* Response found, success. */
 			return 0;
+		} else if (cyapa->operational && input && input->users &&
+			   (pm_stage == CYAPA_PM_RUNTIME_RESUME ||
+			    pm_stage == CYAPA_PM_RUNTIME_SUSPEND)) {
+			/* Parse the data and report it if it's valid. */
+			cyapa_pip_event_process(cyapa,
+			       (struct cyapa_pip_report_data *)pip->empty_buf);
 		}
 
 		error = -EINVAL;
@@ -1566,15 +1612,17 @@ int cyapa_pip_deep_sleep(struct cyapa *cyapa, u8 state)
 }
 
 static int cyapa_gen5_set_power_mode(struct cyapa *cyapa,
-		u8 power_mode, u16 sleep_time, bool is_suspend)
+		u8 power_mode, u16 sleep_time, enum cyapa_pm_stage pm_stage)
 {
 	struct device *dev = &cyapa->client->dev;
 	u8 power_state;
-	int error;
+	int error = 0;
 
 	if (cyapa->state != CYAPA_STATE_GEN5_APP)
 		return 0;
 
+	cyapa_set_pip_pm_state(cyapa, pm_stage);
+
 	if (PIP_DEV_GET_PWR_STATE(cyapa) == UNINIT_PWR_MODE) {
 		/*
 		 * Assume TP in deep sleep mode when driver is loaded,
@@ -1597,7 +1645,7 @@ static int cyapa_gen5_set_power_mode(struct cyapa *cyapa,
 			power_mode == PWR_MODE_BTN_ONLY ||
 			PIP_DEV_GET_SLEEP_TIME(cyapa) == sleep_time) {
 			/* Has in correct power mode state, early return. */
-			return 0;
+			goto out;
 		}
 	}
 
@@ -1605,11 +1653,11 @@ static int cyapa_gen5_set_power_mode(struct cyapa *cyapa,
 		error = cyapa_pip_deep_sleep(cyapa, PIP_DEEP_SLEEP_STATE_OFF);
 		if (error) {
 			dev_err(dev, "enter deep sleep fail: %d\n", error);
-			return error;
+			goto out;
 		}
 
 		PIP_DEV_SET_PWR_STATE(cyapa, PWR_MODE_OFF);
-		return 0;
+		goto out;
 	}
 
 	/*
@@ -1621,7 +1669,7 @@ static int cyapa_gen5_set_power_mode(struct cyapa *cyapa,
 		error = cyapa_pip_deep_sleep(cyapa, PIP_DEEP_SLEEP_STATE_ON);
 		if (error) {
 			dev_err(dev, "deep sleep wake fail: %d\n", error);
-			return error;
+			goto out;
 		}
 	}
 
@@ -1630,7 +1678,7 @@ static int cyapa_gen5_set_power_mode(struct cyapa *cyapa,
 				GEN5_POWER_STATE_ACTIVE);
 		if (error) {
 			dev_err(dev, "change to active fail: %d\n", error);
-			return error;
+			goto out;
 		}
 
 		PIP_DEV_SET_PWR_STATE(cyapa, PWR_MODE_FULL_ACTIVE);
@@ -1639,7 +1687,7 @@ static int cyapa_gen5_set_power_mode(struct cyapa *cyapa,
 				GEN5_POWER_STATE_BTN_ONLY);
 		if (error) {
 			dev_err(dev, "fail to button only mode: %d\n", error);
-			return error;
+			goto out;
 		}
 
 		PIP_DEV_SET_PWR_STATE(cyapa, PWR_MODE_BTN_ONLY);
@@ -1664,7 +1712,7 @@ static int cyapa_gen5_set_power_mode(struct cyapa *cyapa,
 		if (error) {
 			dev_err(dev, "set power state to 0x%02x failed: %d\n",
 				power_state, error);
-			return error;
+			goto out;
 		}
 
 		/*
@@ -1677,14 +1725,16 @@ static int cyapa_gen5_set_power_mode(struct cyapa *cyapa,
 		 * is suspending which may cause interrupt line unable to be
 		 * asserted again.
 		 */
-		if (is_suspend)
+		if (pm_stage == CYAPA_PM_SUSPEND)
 			cyapa_gen5_disable_pip_report(cyapa);
 
 		PIP_DEV_SET_PWR_STATE(cyapa,
 			cyapa_sleep_time_to_pwr_cmd(sleep_time));
 	}
 
-	return 0;
+out:
+	cyapa_reset_pip_pm_state(cyapa);
+	return error;
 }
 
 int cyapa_pip_resume_scanning(struct cyapa *cyapa)
@@ -2513,7 +2563,7 @@ static int cyapa_gen5_do_operational_check(struct cyapa *cyapa)
 		 * the device state is required.
 		 */
 		error = cyapa_gen5_set_power_mode(cyapa,
-				PWR_MODE_FULL_ACTIVE, 0, false);
+				PWR_MODE_FULL_ACTIVE, 0, CYAPA_PM_ACTIVE);
 		if (error)
 			dev_warn(dev, "%s: failed to set power active mode.\n",
 				__func__);
@@ -2715,7 +2765,6 @@ int cyapa_pip_irq_handler(struct cyapa *cyapa)
 	struct device *dev = &cyapa->client->dev;
 	struct cyapa_pip_report_data report_data;
 	unsigned int report_len;
-	u8 report_id;
 	int ret;
 
 	if (!cyapa_is_pip_app_mode(cyapa)) {
@@ -2752,7 +2801,23 @@ int cyapa_pip_irq_handler(struct cyapa *cyapa)
 		return -EINVAL;
 	}
 
-	report_id = report_data.report_head[PIP_RESP_REPORT_ID_OFFSET];
+	return cyapa_pip_event_process(cyapa, &report_data);
+}
+
+static int cyapa_pip_event_process(struct cyapa *cyapa,
+				   struct cyapa_pip_report_data *report_data)
+{
+	struct device *dev = &cyapa->client->dev;
+	unsigned int report_len;
+	u8 report_id;
+
+	report_len = get_unaligned_le16(
+			&report_data->report_head[PIP_RESP_LENGTH_OFFSET]);
+	/* Idle, no data for report. */
+	if (report_len == PIP_RESP_LENGTH_SIZE)
+		return 0;
+
+	report_id = report_data->report_head[PIP_RESP_REPORT_ID_OFFSET];
 	if (report_id == PIP_WAKEUP_EVENT_REPORT_ID &&
 			report_len == PIP_WAKEUP_EVENT_SIZE) {
 		/*
@@ -2805,11 +2870,11 @@ int cyapa_pip_irq_handler(struct cyapa *cyapa)
 	}
 
 	if (report_id == PIP_TOUCH_REPORT_ID)
-		cyapa_pip_report_touches(cyapa, &report_data);
+		cyapa_pip_report_touches(cyapa, report_data);
 	else if (report_id == PIP_PROXIMITY_REPORT_ID)
-		cyapa_pip_report_proximity(cyapa, &report_data);
+		cyapa_pip_report_proximity(cyapa, report_data);
 	else
-		cyapa_pip_report_buttons(cyapa, &report_data);
+		cyapa_pip_report_buttons(cyapa, report_data);
 
 	return 0;
 }