Prepare for multiple video streams from the same sensor by adding a use counter to each subdevice. The counter is increased for every s_stream(1) and decremented for every s_stream(0) call.
The subdevice stream is not started or stopped unless the usage count go from 0 to 1 (started) or from 1 to 0 (stopped). This allows for multiple s_stream() calls to try to either start or stop the device while only the first/last call will actually effect the state of the device. [Kaaira: rebased the patch on current HEAD of media-tree (8f2a4a9d5ff5202d0b3e3a144ebb9b67aabadd29)] Signed-off-by: Niklas Söderlund <niklas.soderl...@ragnatech.se> Signed-off-by: Kaaira Gupta <kgu...@es.iitr.ac.in> --- drivers/media/test-drivers/vimc/vimc-debayer.c | 8 ++++++++ drivers/media/test-drivers/vimc/vimc-scaler.c | 8 ++++++++ drivers/media/test-drivers/vimc/vimc-sensor.c | 9 ++++++++- 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/media/test-drivers/vimc/vimc-debayer.c b/drivers/media/test-drivers/vimc/vimc-debayer.c index c3f6fef34f68..93fe19d8d2b4 100644 --- a/drivers/media/test-drivers/vimc/vimc-debayer.c +++ b/drivers/media/test-drivers/vimc/vimc-debayer.c @@ -29,6 +29,7 @@ struct vimc_deb_pix_map { struct vimc_deb_device { struct vimc_ent_device ved; struct v4l2_subdev sd; + atomic_t use_count; /* The active format */ struct v4l2_mbus_framefmt sink_fmt; u32 src_code; @@ -343,6 +344,9 @@ static int vimc_deb_s_stream(struct v4l2_subdev *sd, int enable) const struct vimc_pix_map *vpix; unsigned int frame_size; + if (atomic_inc_return(&vdeb->use_count) != 1) + return 0; + if (vdeb->src_frame) return 0; @@ -368,6 +372,9 @@ static int vimc_deb_s_stream(struct v4l2_subdev *sd, int enable) return -ENOMEM; } else { + if (atomic_dec_return(&vdeb->use_count) != 0) + return 0; + if (!vdeb->src_frame) return 0; @@ -595,6 +602,7 @@ static struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc, vdeb->ved.process_frame = vimc_deb_process_frame; vdeb->ved.dev = vimc->mdev.dev; vdeb->mean_win_size = vimc_deb_ctrl_mean_win_size.def; + atomic_set(&vdeb->use_count, 0); /* Initialize the frame format */ vdeb->sink_fmt = sink_fmt_default; diff --git a/drivers/media/test-drivers/vimc/vimc-scaler.c b/drivers/media/test-drivers/vimc/vimc-scaler.c index 121fa7d62a2e..9b8458dbe57c 100644 --- a/drivers/media/test-drivers/vimc/vimc-scaler.c +++ b/drivers/media/test-drivers/vimc/vimc-scaler.c @@ -25,6 +25,7 @@ MODULE_PARM_DESC(sca_mult, " the image size multiplier"); struct vimc_sca_device { struct vimc_ent_device ved; struct v4l2_subdev sd; + atomic_t use_count; /* NOTE: the source fmt is the same as the sink * with the width and hight multiplied by mult */ @@ -340,6 +341,9 @@ static int vimc_sca_s_stream(struct v4l2_subdev *sd, int enable) const struct vimc_pix_map *vpix; unsigned int frame_size; + if (atomic_inc_return(&vsca->use_count) != 1) + return 0; + if (vsca->src_frame) return 0; @@ -363,6 +367,9 @@ static int vimc_sca_s_stream(struct v4l2_subdev *sd, int enable) return -ENOMEM; } else { + if (atomic_dec_return(&vsca->use_count) != 0) + return 0; + if (!vsca->src_frame) return 0; @@ -506,6 +513,7 @@ static struct vimc_ent_device *vimc_sca_add(struct vimc_device *vimc, vsca->ved.process_frame = vimc_sca_process_frame; vsca->ved.dev = vimc->mdev.dev; + atomic_set(&vsca->use_count, 0); /* Initialize the frame format */ vsca->sink_fmt = sink_fmt_default; diff --git a/drivers/media/test-drivers/vimc/vimc-sensor.c b/drivers/media/test-drivers/vimc/vimc-sensor.c index ba5db5a150b4..dbe169604e71 100644 --- a/drivers/media/test-drivers/vimc/vimc-sensor.c +++ b/drivers/media/test-drivers/vimc/vimc-sensor.c @@ -24,6 +24,7 @@ struct vimc_sen_device { struct vimc_ent_device ved; struct v4l2_subdev sd; struct tpg_data tpg; + atomic_t use_count; u8 *frame; enum vimc_sen_osd_mode osd_value; u64 start_stream_ts; @@ -250,8 +251,10 @@ static int vimc_sen_s_stream(struct v4l2_subdev *sd, int enable) const struct vimc_pix_map *vpix; unsigned int frame_size; - vsen->start_stream_ts = ktime_get_ns(); + if (atomic_inc_return(&vsen->use_count) != 1) + return 0; + vsen->start_stream_ts = ktime_get_ns(); /* Calculate the frame size */ vpix = vimc_pix_map_by_code(vsen->mbus_format.code); frame_size = vsen->mbus_format.width * vpix->bpp * @@ -270,6 +273,9 @@ static int vimc_sen_s_stream(struct v4l2_subdev *sd, int enable) } else { + if (atomic_dec_return(&vsen->use_count) != 0) + return 0; + vfree(vsen->frame); vsen->frame = NULL; } @@ -430,6 +436,7 @@ static struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc, vsen->ved.process_frame = vimc_sen_process_frame; vsen->ved.dev = vimc->mdev.dev; + atomic_set(&vsen->use_count, 0); /* Initialize the frame format */ vsen->mbus_format = fmt_default; -- 2.17.1