Wall time obtained from do_gettimeofday is susceptible to sudden jumps due to
user setting the time or due to NTP.
Monotonic time is constantly increasing time better suited for comparing two
timestamps.
Signed-off-by: Abhilash Jindal <klock.android@xxxxxxxxx>
---
drivers/staging/comedi/drivers/serial2002.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/staging/comedi/drivers/serial2002.c b/drivers/staging/comedi/drivers/serial2002.c
index 83da162..5f19374 100644
--- a/drivers/staging/comedi/drivers/serial2002.c
+++ b/drivers/staging/comedi/drivers/serial2002.c
@@ -32,6 +32,7 @@ Status: in development
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/ktime.h>
#include <linux/termios.h>
#include <asm/ioctls.h>
@@ -121,9 +122,9 @@ static int serial2002_tty_write(struct file *f, unsigned char *buf, int count)
static void serial2002_tty_read_poll_wait(struct file *f, int timeout)
{
struct poll_wqueues table;
- struct timeval start, now;
+ ktime_t start, now;
- do_gettimeofday(&start);
+ start = ktime_get();
poll_initwait(&table);
while (1) {
long elapsed;
@@ -134,9 +135,8 @@ static void serial2002_tty_read_poll_wait(struct file *f, int timeout)
POLLHUP | POLLERR)) {
break;
}
- do_gettimeofday(&now);
- elapsed = 1000000 * (now.tv_sec - start.tv_sec) +
- now.tv_usec - start.tv_usec;
+ now = ktime_get();
+ elapsed = ktime_us_delta(now, start);
if (elapsed > timeout)
break;
set_current_state(TASK_INTERRUPTIBLE);
--
1.7.9.5
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