diff options
| author | Abhilash Jindal <klock.android@gmail.com> | 2016-01-27 23:46:02 +0100 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2016-02-01 21:16:13 +0100 |
| commit | 17a2f46c3d8877fe2a0b6ff391d1df30e67892a6 (patch) | |
| tree | b9157688a9f3e3ebe04306ea2db4c5746708db50 | |
| parent | iio: imu: Fix dependencies for !HAS_IOMEM archs (diff) | |
| download | linux-17a2f46c3d8877fe2a0b6ff391d1df30e67892a6.tar.xz linux-17a2f46c3d8877fe2a0b6ff391d1df30e67892a6.zip | |
iio: dht11: Use boottime
Wall time obtained from ktime_get_real_ns is susceptible to sudden jumps due to
user setting the time or due to NTP. Boot time is constantly increasing time
better suited for comparing two timestamps.
Signed-off-by: Abhilash Jindal <klock.android@gmail.com>
Reviewed-by: Harald Geyer <harald@ccbib.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
| -rw-r--r-- | drivers/iio/humidity/dht11.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/iio/humidity/dht11.c b/drivers/iio/humidity/dht11.c index 1165b1c4f9d6..cfc5a051ab9f 100644 --- a/drivers/iio/humidity/dht11.c +++ b/drivers/iio/humidity/dht11.c @@ -117,7 +117,7 @@ static int dht11_decode(struct dht11 *dht11, int offset, int timeres) if (((hum_int + hum_dec + temp_int + temp_dec) & 0xff) != checksum) return -EIO; - dht11->timestamp = ktime_get_real_ns(); + dht11->timestamp = ktime_get_boot_ns(); if (hum_int < 20) { /* DHT22 */ dht11->temperature = (((temp_int & 0x7f) << 8) + temp_dec) * ((temp_int & 0x80) ? -100 : 100); @@ -145,7 +145,7 @@ static irqreturn_t dht11_handle_irq(int irq, void *data) /* TODO: Consider making the handler safe for IRQ sharing */ if (dht11->num_edges < DHT11_EDGES_PER_READ && dht11->num_edges >= 0) { - dht11->edges[dht11->num_edges].ts = ktime_get_real_ns(); + dht11->edges[dht11->num_edges].ts = ktime_get_boot_ns(); dht11->edges[dht11->num_edges++].value = gpio_get_value(dht11->gpio); @@ -164,7 +164,7 @@ static int dht11_read_raw(struct iio_dev *iio_dev, int ret, timeres; mutex_lock(&dht11->lock); - if (dht11->timestamp + DHT11_DATA_VALID_TIME < ktime_get_real_ns()) { + if (dht11->timestamp + DHT11_DATA_VALID_TIME < ktime_get_boot_ns()) { timeres = ktime_get_resolution_ns(); if (DHT11_DATA_BIT_HIGH < 2 * timeres) { dev_err(dht11->dev, "timeresolution %dns too low\n", @@ -279,7 +279,7 @@ static int dht11_probe(struct platform_device *pdev) return -EINVAL; } - dht11->timestamp = ktime_get_real_ns() - DHT11_DATA_VALID_TIME - 1; + dht11->timestamp = ktime_get_boot_ns() - DHT11_DATA_VALID_TIME - 1; dht11->num_edges = -1; platform_set_drvdata(pdev, iio); |