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Subject[PATCH 2/8] [media] uvc_video: use ktime_t for timestamps
Date
uvc_video_get_ts() returns a 'struct timespec', but all its users
really want a nanoseconds variable anyway.

Changing the deprecated ktime_get_ts/ktime_get_real_ts to ktime_get
and ktime_get_real simplifies the code noticeably, while keeping
the resulting numbers unchanged.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/media/usb/uvc/uvc_video.c | 37 ++++++++++++-------------------------
drivers/media/usb/uvc/uvcvideo.h | 2 +-
2 files changed, 13 insertions(+), 26 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index d6bee37cd1b8..f7a919490b2b 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -369,12 +369,12 @@ static int uvc_commit_video(struct uvc_streaming *stream,
* Clocks and timestamps
*/

-static inline void uvc_video_get_ts(struct timespec *ts)
+static inline ktime_t uvc_video_get_time(void)
{
if (uvc_clock_param == CLOCK_MONOTONIC)
- ktime_get_ts(ts);
+ return ktime_get();
else
- ktime_get_real_ts(ts);
+ return ktime_get_real();
}

static void
@@ -386,7 +386,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
bool has_pts = false;
bool has_scr = false;
unsigned long flags;
- struct timespec ts;
+ ktime_t time;
u16 host_sof;
u16 dev_sof;

@@ -436,7 +436,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
stream->clock.last_sof = dev_sof;

host_sof = usb_get_current_frame_number(stream->dev->udev);
- uvc_video_get_ts(&ts);
+ time = uvc_video_get_time();

/* The UVC specification allows device implementations that can't obtain
* the USB frame number to keep their own frame counters as long as they
@@ -473,7 +473,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
sample->dev_stc = get_unaligned_le32(&data[header_size - 6]);
sample->dev_sof = dev_sof;
sample->host_sof = host_sof;
- sample->host_ts = ts;
+ sample->host_time = time;

/* Update the sliding window head and count. */
stream->clock.head = (stream->clock.head + 1) % stream->clock.size;
@@ -613,14 +613,12 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
struct uvc_clock_sample *first;
struct uvc_clock_sample *last;
unsigned long flags;
- struct timespec ts;
+ u64 timestamp;
u32 delta_stc;
u32 y1, y2;
u32 x1, x2;
u32 mean;
u32 sof;
- u32 div;
- u32 rem;
u64 y;

if (!uvc_hw_timestamps_param)
@@ -667,9 +665,8 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
if (x1 == x2)
goto done;

- ts = timespec_sub(last->host_ts, first->host_ts);
y1 = NSEC_PER_SEC;
- y2 = (ts.tv_sec + 1) * NSEC_PER_SEC + ts.tv_nsec;
+ y2 = (u32)ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1;

/* Interpolated and host SOF timestamps can wrap around at slightly
* different times. Handle this by adding or removing 2048 to or from
@@ -686,24 +683,18 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
- (u64)y2 * (u64)x1;
y = div_u64(y, x2 - x1);

- div = div_u64_rem(y, NSEC_PER_SEC, &rem);
- ts.tv_sec = first->host_ts.tv_sec - 1 + div;
- ts.tv_nsec = first->host_ts.tv_nsec + rem;
- if (ts.tv_nsec >= NSEC_PER_SEC) {
- ts.tv_sec++;
- ts.tv_nsec -= NSEC_PER_SEC;
- }
+ timestamp = ktime_to_ns(first->host_time) + y - y1;

uvc_trace(UVC_TRACE_CLOCK, "%s: SOF %u.%06llu y %llu ts %llu "
"buf ts %llu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n",
stream->dev->name,
sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),
- y, timespec_to_ns(&ts), vbuf->vb2_buf.timestamp,
+ y, timestamp, vbuf->vb2_buf.timestamp,
x1, first->host_sof, first->dev_sof,
x2, last->host_sof, last->dev_sof, y1, y2);

/* Update the V4L2 buffer. */
- vbuf->vb2_buf.timestamp = timespec_to_ns(&ts);
+ vbuf->vb2_buf.timestamp = timestamp;

done:
spin_unlock_irqrestore(&clock->lock, flags);
@@ -1007,8 +998,6 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
* when the EOF bit is set to force synchronisation on the next packet.
*/
if (buf->state != UVC_BUF_STATE_ACTIVE) {
- struct timespec ts;
-
if (fid == stream->last_fid) {
uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
"sync).\n");
@@ -1018,11 +1007,9 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
return -ENODATA;
}

- uvc_video_get_ts(&ts);
-
buf->buf.field = V4L2_FIELD_NONE;
buf->buf.sequence = stream->sequence;
- buf->buf.vb2_buf.timestamp = timespec_to_ns(&ts);
+ buf->buf.vb2_buf.timestamp = uvc_video_get_time();

/* TODO: Handle PTS and SCR. */
buf->state = UVC_BUF_STATE_ACTIVE;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index a2c190937067..d7797dfb6468 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -536,8 +536,8 @@ struct uvc_streaming {
struct uvc_clock_sample {
u32 dev_stc;
u16 dev_sof;
- struct timespec host_ts;
u16 host_sof;
+ ktime_t host_time;
} *samples;

unsigned int head;
--
2.9.0
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