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From aa6e148bb75f76291e9625316f1f7c73458daf47 Mon Sep 17 00:00:00 2001
From: David H <davidjhu@gmail.com>
Date: Wed, 4 Oct 2017 04:43:07 -0700
Subject: [PATCH 200/454] bcm2835-camera: Fix timestamp calculation problem
(#2214)
* bcm2835-camera: Fix timestamp calculation problem
Use div_s64_rem() to convert usec timestamp to timeval
to avoid integer signedness bug.
* bcm2835-camera: Store kernel start time in NSEC instead of USEC
* bcm2835-camera: Reword debug message for clarity
---
.../bcm2835-camera/bcm2835-camera.c | 41 +++++--------------
.../bcm2835-camera/bcm2835-camera.h | 2 +-
2 files changed, 11 insertions(+), 32 deletions(-)
--- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
+++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
@@ -348,37 +348,17 @@ static void buffer_cb(struct vchiq_mmal_
buf->vb.vb2_buf.timestamp);
} else if(pts != 0) {
- struct timeval timestamp;
s64 runtime_us = pts -
dev->capture.vc_start_timestamp;
- u32 div = 0;
- u32 rem = 0;
-
- div =
- div_u64_rem(runtime_us, USEC_PER_SEC, &rem);
- timestamp.tv_sec =
- dev->capture.kernel_start_ts.tv_sec + div;
- timestamp.tv_usec =
- dev->capture.kernel_start_ts.tv_usec + rem;
-
- if (timestamp.tv_usec >=
- USEC_PER_SEC) {
- timestamp.tv_sec++;
- timestamp.tv_usec -=
- USEC_PER_SEC;
- }
+ buf->vb.vb2_buf.timestamp = (runtime_us * NSEC_PER_USEC) +
+ dev->capture.kernel_start_timestamp;
v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
- "Convert start time %d.%06d and %llu "
- "with offset %llu to %d.%06d\n",
- (int)dev->capture.kernel_start_ts.
- tv_sec,
- (int)dev->capture.kernel_start_ts.
- tv_usec,
- dev->capture.vc_start_timestamp, pts,
- (int)timestamp.tv_sec,
- (int)timestamp.tv_usec);
- buf->vb.vb2_buf.timestamp = timestamp.tv_sec * 1000000000ULL +
- timestamp.tv_usec * 1000ULL;
+ "Buffer time set as converted timestamp - %llu "
+ "= (pts [%lld usec] - vc start time [%llu usec]) "
+ "+ kernel start time [%llu nsec]\n",
+ buf->vb.vb2_buf.timestamp,
+ pts, dev->capture.vc_start_timestamp,
+ dev->capture.kernel_start_timestamp);
} else {
if (dev->capture.last_timestamp) {
buf->vb.vb2_buf.timestamp = dev->capture.last_timestamp;
@@ -388,8 +368,7 @@ static void buffer_cb(struct vchiq_mmal_
}
else {
buf->vb.vb2_buf.timestamp =
- dev->capture.kernel_start_ts.tv_sec * 1000000000ULL +
- dev->capture.kernel_start_ts.tv_usec * 1000ULL;
+ dev->capture.kernel_start_timestamp;
v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
"Buffer time set as start timestamp - %lld",
buf->vb.vb2_buf.timestamp);
@@ -574,7 +553,7 @@ static int start_streaming(struct vb2_qu
dev->capture.last_timestamp = 0;
- v4l2_get_timestamp(&dev->capture.kernel_start_ts);
+ dev->capture.kernel_start_timestamp = ktime_get_ns();
/* enable the camera port */
dev->capture.port->cb_ctx = dev;
--- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.h
+++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.h
@@ -92,7 +92,7 @@ struct bm2835_mmal_dev {
/* VC start timestamp for streaming */
s64 vc_start_timestamp;
/* Kernel start timestamp for streaming */
- struct timeval kernel_start_ts;
+ u64 kernel_start_timestamp;
/* Timestamp of last frame */
u64 last_timestamp;
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