Re: [PATCH v2] [media] staging: atomisp: convert timestamps to ktime_t

From: Andy Shevchenko
Date: Mon Nov 27 2017 - 10:25:47 EST


On Mon, 2017-11-27 at 16:21 +0100, Arnd Bergmann wrote:
> timespec overflows in 2038 on 32-bit architectures, and the
> getnstimeofday() suffers from possible time jumps, so the
> timestamps here are better done using ktime_get(), which has
> neither of those problems.
>
> In case of ov2680, we don't seem to use the timestamp at
> all, so I just remove it.
>

Yep,

Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> v2: use min_t() as suggested by Andy Shevchenko
> ---
> drivers/staging/media/atomisp/i2c/ov2680.h | 1 -
> .../staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c | 19 ++++++++
> -----------
> drivers/staging/media/atomisp/i2c/ov5693/ov5693.h | 2 +-
> 3 files changed, 9 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/staging/media/atomisp/i2c/ov2680.h
> b/drivers/staging/media/atomisp/i2c/ov2680.h
> index bf4897347df7..03f75dd80f87 100644
> --- a/drivers/staging/media/atomisp/i2c/ov2680.h
> +++ b/drivers/staging/media/atomisp/i2c/ov2680.h
> @@ -174,7 +174,6 @@ struct ov2680_format {
> struct mutex input_lock;
> struct v4l2_ctrl_handler ctrl_handler;
> struct camera_sensor_platform_data *platform_data;
> - struct timespec timestamp_t_focus_abs;
> int vt_pix_clk_freq_mhz;
> int fmt_idx;
> int run_mode;
> diff --git a/drivers/staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c
> b/drivers/staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c
> index 3e7c3851280f..9fa25bb8f1ee 100644
> --- a/drivers/staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c
> +++ b/drivers/staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c
> @@ -973,7 +973,7 @@ static int ov5693_t_focus_abs(struct v4l2_subdev
> *sd, s32 value)
> if (ret == 0) {
> dev->number_of_steps = value - dev->focus;
> dev->focus = value;
> - getnstimeofday(&(dev->timestamp_t_focus_abs));
> + dev->timestamp_t_focus_abs = ktime_get();
> } else
> dev_err(&client->dev,
> "%s: i2c failed. ret %d\n", __func__, ret);
> @@ -993,16 +993,13 @@ static int ov5693_q_focus_status(struct
> v4l2_subdev *sd, s32 *value)
> {
> u32 status = 0;
> struct ov5693_device *dev = to_ov5693_sensor(sd);
> - struct timespec temptime;
> - const struct timespec timedelay = {
> - 0,
> - min((u32)abs(dev->number_of_steps) *
> DELAY_PER_STEP_NS,
> - (u32)DELAY_MAX_PER_STEP_NS),
> - };
> -
> - getnstimeofday(&temptime);
> - temptime = timespec_sub(temptime, (dev-
> >timestamp_t_focus_abs));
> - if (timespec_compare(&temptime, &timedelay) <= 0) {
> + ktime_t temptime;
> + ktime_t timedelay = ns_to_ktime(min_t(u32,
> + abs(dev->number_of_steps) *
> DELAY_PER_STEP_NS,
> + DELAY_MAX_PER_STEP_NS));
> +
> + temptime = ktime_sub(ktime_get(), (dev-
> >timestamp_t_focus_abs));
> + if (ktime_compare(temptime, timedelay) <= 0) {
> status |= ATOMISP_FOCUS_STATUS_MOVING;
> status |= ATOMISP_FOCUS_HP_IN_PROGRESS;
> } else {
> diff --git a/drivers/staging/media/atomisp/i2c/ov5693/ov5693.h
> b/drivers/staging/media/atomisp/i2c/ov5693/ov5693.h
> index 2ea63807c56d..68cfcb4a6c3c 100644
> --- a/drivers/staging/media/atomisp/i2c/ov5693/ov5693.h
> +++ b/drivers/staging/media/atomisp/i2c/ov5693/ov5693.h
> @@ -221,7 +221,7 @@ struct ov5693_device {
> struct v4l2_ctrl_handler ctrl_handler;
>
> struct camera_sensor_platform_data *platform_data;
> - struct timespec timestamp_t_focus_abs;
> + ktime_t timestamp_t_focus_abs;
> int vt_pix_clk_freq_mhz;
> int fmt_idx;
> int run_mode;

--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy