[PATCH v4 1/5] gnss: sirf: write data to gnss only when the gnss device is open

From: Andreas Kemnade
Date: Thu Jan 24 2019 - 01:35:13 EST


The api forbids writing data there otherwise. Prepare for the
serdev_open()/close() being a part of sirf_set_active.

Signed-off-by: Andreas Kemnade <andreas@xxxxxxxxxxxx>
---
No changes in v4
Changes in v3:
- add more locking
- style cleanup
- mutex *not* renamed since we need a second one

Changes in v2:
- add locking

drivers/gnss/sirf.c | 32 ++++++++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c
index 59cde7e923b8..49bc021325e9 100644
--- a/drivers/gnss/sirf.c
+++ b/drivers/gnss/sirf.c
@@ -35,6 +35,10 @@ struct sirf_data {
struct gpio_desc *wakeup;
int irq;
bool active;
+
+ struct mutex gdev_mutex;
+ bool open;
+
wait_queue_head_t power_wait;
};

@@ -44,9 +48,18 @@ static int sirf_open(struct gnss_device *gdev)
struct serdev_device *serdev = data->serdev;
int ret;

+ mutex_lock(&data->gdev_mutex);
+ data->open = true;
+ mutex_unlock(&data->gdev_mutex);
+
ret = serdev_device_open(serdev);
- if (ret)
+ if (ret) {
+ mutex_lock(&data->gdev_mutex);
+ data->open = false;
+ mutex_unlock(&data->gdev_mutex);
return ret;
+ }
+

serdev_device_set_baudrate(serdev, data->speed);
serdev_device_set_flow_control(serdev, false);
@@ -63,6 +76,10 @@ static int sirf_open(struct gnss_device *gdev)
err_close:
serdev_device_close(serdev);

+ mutex_lock(&data->gdev_mutex);
+ data->open = false;
+ mutex_unlock(&data->gdev_mutex);
+
return ret;
}

@@ -74,6 +91,10 @@ static void sirf_close(struct gnss_device *gdev)
serdev_device_close(serdev);

pm_runtime_put(&serdev->dev);
+
+ mutex_lock(&data->gdev_mutex);
+ data->open = false;
+ mutex_unlock(&data->gdev_mutex);
}

static int sirf_write_raw(struct gnss_device *gdev, const unsigned char *buf,
@@ -105,8 +126,14 @@ static int sirf_receive_buf(struct serdev_device *serdev,
{
struct sirf_data *data = serdev_device_get_drvdata(serdev);
struct gnss_device *gdev = data->gdev;
+ int ret = 0;

- return gnss_insert_raw(gdev, buf, count);
+ mutex_lock(&data->gdev_mutex);
+ if (data->open)
+ ret = gnss_insert_raw(gdev, buf, count);
+ mutex_unlock(&data->gdev_mutex);
+
+ return ret;
}

static const struct serdev_device_ops sirf_serdev_ops = {
@@ -275,6 +302,7 @@ static int sirf_probe(struct serdev_device *serdev)
data->serdev = serdev;
data->gdev = gdev;

+ mutex_init(&data->gdev_mutex);
init_waitqueue_head(&data->power_wait);

serdev_device_set_drvdata(serdev, data);
--
2.11.0