From: Andreas Kemnade <andreas@kemnade.info>
To: johan@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Discussions about the Letux Kernel
<letux-kernel@openphoenux.org>
Cc: Andreas Kemnade <andreas@kemnade.info>
Subject: [PATCH v2 1/5] gnss: sirf: write data to gnss only when the gnss device is open
Date: Sun, 9 Dec 2018 20:51:46 +0100 [thread overview]
Message-ID: <20181209195150.5192-2-andreas@kemnade.info> (raw)
In-Reply-To: <20181209195150.5192-1-andreas@kemnade.info>
The api forbids writing data there otherwise. Prepare for the
serdev_open()/close() being a part of runtime pm.
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
Changes in v2:
add locking
drivers/gnss/sirf.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c
index 2c22836d3ffd..ba663de1db49 100644
--- a/drivers/gnss/sirf.c
+++ b/drivers/gnss/sirf.c
@@ -35,6 +35,12 @@ struct sirf_data {
struct gpio_desc *wakeup;
int irq;
bool active;
+ /*
+ * There might be races between returning data and closing the gnss
+ * device.
+ */
+ struct mutex gdev_mutex;
+ bool opened;
wait_queue_head_t power_wait;
};
@@ -44,6 +50,7 @@ static int sirf_open(struct gnss_device *gdev)
struct serdev_device *serdev = data->serdev;
int ret;
+ data->opened = true;
ret = serdev_device_open(serdev);
if (ret)
return ret;
@@ -55,6 +62,7 @@ static int sirf_open(struct gnss_device *gdev)
if (ret < 0) {
dev_err(&gdev->dev, "failed to runtime resume: %d\n", ret);
pm_runtime_put_noidle(&serdev->dev);
+ data->opened = false;
goto err_close;
}
@@ -74,6 +82,9 @@ static void sirf_close(struct gnss_device *gdev)
serdev_device_close(serdev);
pm_runtime_put(&serdev->dev);
+ mutex_lock(&data->gdev_mutex);
+ data->opened = false;
+ mutex_unlock(&data->gdev_mutex);
}
static int sirf_write_raw(struct gnss_device *gdev, const unsigned char *buf,
@@ -105,8 +116,22 @@ 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;
+
+ /*
+ * we might come here everytime when runtime is resumed
+ * and data is received. Two cases are possible
+ * 1. device is opened during initialisation
+ * 2. kernel is compiled without runtime pm
+ * and device is opened all the time
+ */
+ mutex_lock(&data->gdev_mutex);
+ if (data->opened)
+ ret = gnss_insert_raw(gdev, buf, count);
- return gnss_insert_raw(gdev, buf, count);
+ mutex_unlock(&data->gdev_mutex);
+
+ return ret;
}
static const struct serdev_device_ops sirf_serdev_ops = {
@@ -275,6 +300,7 @@ 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
next prev parent reply other threads:[~2018-12-09 19:52 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-09 19:51 [PATCH v2 0/5] gnss: sirf: add support for w2sg0004 + lna Andreas Kemnade
2018-12-09 19:51 ` Andreas Kemnade [this message]
2019-01-10 12:02 ` [PATCH v2 1/5] gnss: sirf: write data to gnss only when the gnss device is open Johan Hovold
2019-01-13 20:50 ` Andreas Kemnade
2019-01-14 12:00 ` Johan Hovold
2018-12-09 19:51 ` [PATCH v2 2/5] gnss: sirf: power on logic for devices without wakeup signal Andreas Kemnade
2019-01-10 12:10 ` Johan Hovold
2019-01-10 22:02 ` Andreas Kemnade
2019-01-14 10:51 ` Johan Hovold
2019-01-14 12:13 ` Andreas Kemnade
2019-01-22 8:38 ` Johan Hovold
2019-01-14 21:58 ` Andreas Kemnade
2019-01-15 9:08 ` Johan Hovold
2018-12-09 19:51 ` [PATCH v2 3/5] dt-bindings: gnss: add w2sg0004 compatible string Andreas Kemnade
2019-01-10 12:12 ` Johan Hovold
2018-12-09 19:51 ` [PATCH v2 4/5] gnss: sirf: add a separate supply for a lna Andreas Kemnade
2018-12-10 7:42 ` [Letux-kernel] " H. Nikolaus Schaller
2019-01-10 12:25 ` Johan Hovold
2018-12-09 19:51 ` [PATCH v2 5/5] dt-bindings: gnss: add lna-supply property Andreas Kemnade
2019-01-10 12:27 ` Johan Hovold
2019-01-10 17:07 ` Andreas Kemnade
2019-01-14 9:15 ` Johan Hovold
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