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

diff --git a/drivers/media/platform/bcm2835/bcm2835-camera.c b/drivers/media/platform/bcm2835/bcm2835-camera.c
index 6bdec0806126044cf7146d53326e4da5b4269884..5b68abbf9e45ce5cefc14789bdc9c6e889ae0094 100644 (file)
--- a/drivers/media/platform/bcm2835/bcm2835-camera.c
+++ b/drivers/media/platform/bcm2835/bcm2835-camera.c
@@ -363,37 +363,17 @@ static void buffer_cb(struct vchiq_mmal_instance *instance,
                                 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;
@@ -403,8 +383,7 @@ static void buffer_cb(struct vchiq_mmal_instance *instance,
                                }
                                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);
@@ -586,7 +565,7 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 
        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;

diff --git a/drivers/media/platform/bcm2835/bcm2835-camera.h b/drivers/media/platform/bcm2835/bcm2835-camera.h
index 7f8a68916a67001bc9241bce2928519a2ce1ba78..d1b2a675e41d9d6561f278bd9d2f1802d8793f23 100644 (file)
--- a/drivers/media/platform/bcm2835/bcm2835-camera.h
+++ b/drivers/media/platform/bcm2835/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;