lkml.org 
[lkml]   [2019]   [Feb]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v4] media: vimc: Add vimc-streamer for stream control
From
Date
Hi Lucas,

On 1/22/19 2:05 AM, Lucas A. M. Magalhaes wrote:
> Add a linear pipeline logic for the stream control. It's created by
> walking backwards on the entity graph. When the stream starts it will
> simply loop through the pipeline calling the respective process_frame
> function of each entity.
>
> Fixes: f2fe89061d797 ("vimc: Virtual Media Controller core, capture
> and sensor")
> Cc: stable@vger.kernel.org # for v4.20
> Signed-off-by: Lucas A. M. Magalhães <lucmaga@gmail.com>
> ---
>
> The actual approach for streaming frames on vimc uses a recursive
> logic[1]. This algorithm may cause problems as the stack usage
> increases a with the topology. For the actual topology almost 1Kb of
> stack is used if compiled with KASAN on a 64bit architecture. However
> the topology is fixed and hard-coded on vimc-core[2]. So it's a
> controlled situation if used as is.
>
> [1]
> The stream starts on vim-sensor's thread
> https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/vimc/vimc-sensor.c#n204
> It proceeds calling successively vimc_propagate_frame
> https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/vimc/vimc-common.c#n210
> Then processes_frame on the next entity
> https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/vimc/vimc-scaler.c#n349
> https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/vimc/vimc-debayer.c#n483
> This goes until the loop ends on a vimc-capture device
> https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/vimc/vimc-capture.c#n358
>
> [2]https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/vimc/vimc-core.c#n80
>
> Thanks the review Helen. I've made the change you pointed out. There was really
> a bug for single entity pipelines.
>
> Changed from v3:
> * Fix vimc_streamer_pipeline_init and vimc_streamer_pipeline_terminate for a
> single entity pipeline.
> * Remove unnecessary checks and comments.
> * Alignment and style.
>
> drivers/media/platform/vimc/Makefile | 3 +-
> drivers/media/platform/vimc/vimc-capture.c | 18 +-
> drivers/media/platform/vimc/vimc-common.c | 35 ----
> drivers/media/platform/vimc/vimc-common.h | 15 +-
> drivers/media/platform/vimc/vimc-debayer.c | 26 +--
> drivers/media/platform/vimc/vimc-scaler.c | 28 +--
> drivers/media/platform/vimc/vimc-sensor.c | 56 ++----
> drivers/media/platform/vimc/vimc-streamer.c | 188 ++++++++++++++++++++
> drivers/media/platform/vimc/vimc-streamer.h | 38 ++++
> 9 files changed, 260 insertions(+), 147 deletions(-)
> create mode 100644 drivers/media/platform/vimc/vimc-streamer.c
> create mode 100644 drivers/media/platform/vimc/vimc-streamer.h
>

<snip>

> diff --git a/drivers/media/platform/vimc/vimc-sensor.c b/drivers/media/platform/vimc/vimc-sensor.c
> index 32ca9c6172b1..93961a1e694f 100644
> --- a/drivers/media/platform/vimc/vimc-sensor.c
> +++ b/drivers/media/platform/vimc/vimc-sensor.c
> @@ -16,8 +16,6 @@
> */
>
> #include <linux/component.h>
> -#include <linux/freezer.h>
> -#include <linux/kthread.h>
> #include <linux/module.h>
> #include <linux/mod_devicetable.h>
> #include <linux/platform_device.h>
> @@ -201,38 +199,27 @@ static const struct v4l2_subdev_pad_ops vimc_sen_pad_ops = {
> .set_fmt = vimc_sen_set_fmt,
> };
>
> -static int vimc_sen_tpg_thread(void *data)
> +static void *vimc_sen_process_frame(struct vimc_ent_device *ved,
> + const void *sink_frame)
> {
> - struct vimc_sen_device *vsen = data;
> - unsigned int i;
> -
> - set_freezable();
> - set_current_state(TASK_UNINTERRUPTIBLE);
> -
> - for (;;) {
> - try_to_freeze();
> - if (kthread_should_stop())
> - break;
> -
> - tpg_fill_plane_buffer(&vsen->tpg, 0, 0, vsen->frame);
> + struct vimc_sen_device *vsen = container_of(ved, struct vimc_sen_device,
> + ved);
> + const struct vimc_pix_map *vpix;
> + unsigned int frame_size;
>
> - /* Send the frame to all source pads */
> - for (i = 0; i < vsen->sd.entity.num_pads; i++)
> - vimc_propagate_frame(&vsen->sd.entity.pads[i],
> - vsen->frame);
> + /* Calculate the frame size */
> + vpix = vimc_pix_map_by_code(vsen->mbus_format.code);
> + frame_size = vsen->mbus_format.width * vpix->bpp *
> + vsen->mbus_format.height;

frame_size is set, but not used:

vimc-sensor.c:208:15: warning: variable 'frame_size' set but not used [-Wunused-but-set-variable]

Can you make a patch fixing this?

I'm not sure how I missed this sparse warning, weird.

>
> - /* 60 frames per second */
> - schedule_timeout(HZ/60);
> - }
> -
> - return 0;
> + tpg_fill_plane_buffer(&vsen->tpg, 0, 0, vsen->frame);
> + return vsen->frame;
> }

Regards,

Hans

\
 
 \ /
  Last update: 2019-02-07 19:08    [W:0.066 / U:29.872 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site