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

[Alan Cox]

On Mon, 27 Nov 2017 16:21:41 +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.
> 
> Signed-off-by: Arnd Bergmann 

Reviewed-by: Alan Cox 

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

[Andy Shevchenko]

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 

> Signed-off-by: Arnd Bergmann 
> ---
> 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(>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 = timespec_sub(temptime, (dev-
> >timestamp_t_focus_abs));
> - if (timespec_compare(, ) <= 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 
Intel Finland Oy

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

[Arnd Bergmann]

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.

Signed-off-by: Arnd Bergmann 
---
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(>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 = timespec_sub(temptime, (dev->timestamp_t_focus_abs));
-   if (timespec_compare(, ) <= 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;
-- 
2.9.0