[PATCH] drm/sti: Use 64-bit timestamps

Tina Ruchandani
2016-04-13T11:45:03Z

'struct timespec' uses a 32-bit field for seconds, which
will overflow in year 2038 and beyond. This patch is part
of a larger attempt to remove instances of timeval, timespec
and time_t, all of which suffer from the y2038 issue, from the
kernel.

Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
---
drivers/gpu/drm/sti/sti_plane.c | 16 +++-------------
drivers/gpu/drm/sti/sti_plane.h | 2 +-
2 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/sti/sti_plane.c b/drivers/gpu/drm/sti/sti_plane.c
index f10c98d..3b46899 100644
--- a/drivers/gpu/drm/sti/sti_plane.c
+++ b/drivers/gpu/drm/sti/sti_plane.c
@@ -45,25 +45,15 @@ const char *sti_plane_to_str(struct sti_plane *plane)

#define STI_FPS_INTERVAL_MS 3000

-static int sti_plane_timespec_ms_diff(struct timespec lhs, struct timespec rhs)
-{
- struct timespec tmp_ts = timespec_sub(lhs, rhs);
- u64 tmp_ns = (u64)timespec_to_ns(&tmp_ts);
-
- do_div(tmp_ns, NSEC_PER_MSEC);
-
- return (u32)tmp_ns;
-}
-
void sti_plane_update_fps(struct sti_plane *plane,
bool new_frame,
bool new_field)
{
- struct timespec now;
+ ktime_t now;
struct sti_fps_info *fps;
int fpks, fipks, ms_since_last, num_frames, num_fields;

- getrawmonotonic(&now);
+ now = ktime_get();

/* Compute number of frame updates */
fps = &plane->fps_info;
@@ -76,7 +66,7 @@ void sti_plane_update_fps(struct sti_plane *plane,
return;

fps->curr_frame_counter++;
- ms_since_last = sti_plane_timespec_ms_diff(now, fps->last_timestamp);
+ ms_since_last = ktime_to_ms(ktime_sub(now, fps->last_timestamp));
num_frames = fps->curr_frame_counter - fps->last_frame_counter;

if (num_frames <= 0 || ms_since_last < STI_FPS_INTERVAL_MS)
diff --git a/drivers/gpu/drm/sti/sti_plane.h b/drivers/gpu/drm/sti/sti_plane.h
index c50a3b9..0a64eb0 100644
--- a/drivers/gpu/drm/sti/sti_plane.h
+++ b/drivers/gpu/drm/sti/sti_plane.h
@@ -57,7 +57,7 @@ struct sti_fps_info {
unsigned int last_frame_counter;
unsigned int curr_field_counter;
unsigned int last_field_counter;
- struct timespec last_timestamp;
+ ktime_t last_timestamp;
char fps_str[FPS_LENGTH];
char fips_str[FPS_LENGTH];
};
--
2.8.0.rc3.226.g39d4020