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iio: common: ssp_sensors: use ktime_get_real_ns() timestamps

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getnstimeofday() suffers from the overflow in y2038 on 32-bit
architectures and requires a conversion into the nanosecond format that
we want here.

This changes ssp_parse_dataframe() to use ktime_get_real_ns() directly,
which does not have that problem.

An open question is what time base should be used here. Normally
timestamps should use ktime_get_ns() or ktime_get_boot_ns() to read
monotonic time instead of "real" time, which suffers from time jumps
due to settimeofday() calls or leap seconds.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Arnd Bergmann
2017-11-27 12:51:48 +01:00
committed by Greg Kroah-Hartman
parent 1b39eacdbd
commit a4493f227d
1 changed files with 1 additions and 4 deletions
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5
drivers/iio/common/ssp_sensors/ssp_spi.c
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@@ -277,12 +277,9 @@ static int ssp_handle_big_data(struct ssp_data *data, char *dataframe, int *idx)
static int ssp_parse_dataframe(struct ssp_data *data, char *dataframe, int len) static int ssp_parse_dataframe(struct ssp_data *data, char *dataframe, int len)
{ {
int idx, sd; int idx, sd;
struct timespec ts;
struct ssp_sensor_data *spd; struct ssp_sensor_data *spd;
struct iio_dev **indio_devs = data->sensor_devs; struct iio_dev **indio_devs = data->sensor_devs;
getnstimeofday(&ts);
for (idx = 0; idx < len;) { for (idx = 0; idx < len;) {
switch (dataframe[idx++]) { switch (dataframe[idx++]) {
case SSP_MSG2AP_INST_BYPASS_DATA: case SSP_MSG2AP_INST_BYPASS_DATA:
@@ -329,7 +326,7 @@ static int ssp_parse_dataframe(struct ssp_data *data, char *dataframe, int len)
} }
if (data->time_syncing) if (data->time_syncing)
data->timestamp = ts.tv_sec * 1000000000ULL + ts.tv_nsec; data->timestamp = ktime_get_real_ns();
return 0; return 0;
} }