On 11/08/15 15:31, Abhilash Jindal wrote:
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.andr...@gmail.com> --- 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);
Thanks, and sorry for the email address mix-up earlier! Reviewed-by: Ian Abbott <abbo...@mev.co.uk> -- -=( Ian Abbott @ MEV Ltd. E-mail: <abbo...@mev.co.uk> )=- -=( Web: http://www.mev.co.uk/ )=- _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
