Hi Andrey,
Thanks for the set.
On Wed, Mar 03, 2021 at 09:08:17PM +0300, Andrey Konovalov wrote:
> This driver uses V4L2_CID_PIXEL_RATE to calculate the CSI2 link frequency,
> but this may give incorrect result in some cases. Use v4l2_get_link_freq()
> instead.
>
> Also the driver used the external_rate field in struct iss_pipeline as a
> flag to prevent excessive v4l2_subdev_call's when processing the frames
> in single-shot mode. Replace the external_rate with external_lfreq, and
> use external_bpp and external_lfreq to call v4l2_subdev_call(get_fmt) and
> v4l2_get_link_freq() respectively only once per iss_video_streamon().
>
> Signed-off-by: Andrey Konovalov <andrey.konovalov@xxxxxxxxxx>
> ---
> drivers/staging/media/omap4iss/iss.c | 12 +-----------
> drivers/staging/media/omap4iss/iss_csiphy.c | 19 ++++++++++++++++---
> drivers/staging/media/omap4iss/iss_video.c | 2 +-
> drivers/staging/media/omap4iss/iss_video.h | 2 +-
> 4 files changed, 19 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/staging/media/omap4iss/iss.c b/drivers/staging/media/omap4iss/iss.c
> index dae9073e7d3c..0eb7b1b5dcc4 100644
> --- a/drivers/staging/media/omap4iss/iss.c
> +++ b/drivers/staging/media/omap4iss/iss.c
> @@ -131,7 +131,7 @@ int omap4iss_get_external_info(struct iss_pipeline *pipe,
> if (!pipe->external)
> return 0;
>
> - if (pipe->external_rate)
> + if (pipe->external_bpp)
> return 0;
>
> memset(&fmt, 0, sizeof(fmt));
> @@ -145,16 +145,6 @@ int omap4iss_get_external_info(struct iss_pipeline *pipe,
>
> pipe->external_bpp = omap4iss_video_format_info(fmt.format.code)->bpp;
>
> - ctrl = v4l2_ctrl_find(pipe->external->ctrl_handler,
> - V4L2_CID_PIXEL_RATE);
> - if (!ctrl) {
> - dev_warn(iss->dev, "no pixel rate control in subdev %s\n",
> - pipe->external->name);
> - return -EPIPE;
> - }
> -
> - pipe->external_rate = v4l2_ctrl_g_ctrl_int64(ctrl);
> -
> return 0;
> }
>
> diff --git a/drivers/staging/media/omap4iss/iss_csiphy.c b/drivers/staging/media/omap4iss/iss_csiphy.c
> index 96f2ce045138..cec0cd21f7e0 100644
> --- a/drivers/staging/media/omap4iss/iss_csiphy.c
> +++ b/drivers/staging/media/omap4iss/iss_csiphy.c
> @@ -119,6 +119,7 @@ int omap4iss_csiphy_config(struct iss_device *iss,
> struct iss_pipeline *pipe = to_iss_pipeline(&csi2_subdev->entity);
> struct iss_v4l2_subdevs_group *subdevs = pipe->external->host_priv;
> struct iss_csiphy_dphy_cfg csi2phy;
> + s64 link_freq;
> int csi2_ddrclk_khz;
> struct iss_csiphy_lanes_cfg *lanes;
> unsigned int used_lanes = 0;
> @@ -193,9 +194,21 @@ int omap4iss_csiphy_config(struct iss_device *iss,
> if (lanes->clk.pos == 0 || used_lanes & (1 << lanes->clk.pos))
> return -EINVAL;
>
> - csi2_ddrclk_khz = pipe->external_rate / 1000
> - / (2 * csi2->phy->used_data_lanes)
> - * pipe->external_bpp;
> + if (!pipe->external_lfreq) {
> + link_freq = v4l2_get_link_freq(pipe->external->ctrl_handler,
I wonder if you could this unconditionally, and remove external_lfreq field
altogether. The same could be done for external_bpp but that's out of scope
for this patch.
> + pipe->external_bpp,
> + 2 * csi2->phy->used_data_lanes);
> + if (link_freq < 0) {
> + dev_warn(iss->dev,
> + "failed to read the link frequency fromn subdev %s\n",
> + pipe->external->name);
> + return -EINVAL;
> + }
> +
> + pipe->external_lfreq = link_freq;
> + }
> +
> + csi2_ddrclk_khz = div_s64(pipe->external_lfreq, 1000);
>
> /*
> * THS_TERM: Programmed value = ceil(12.5 ns/DDRClk period) - 1.
> diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
> index 66975a37dc85..a654c8d18bbc 100644
> --- a/drivers/staging/media/omap4iss/iss_video.c
> +++ b/drivers/staging/media/omap4iss/iss_video.c
> @@ -872,7 +872,7 @@ iss_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
> pipe = entity->pipe
> ? to_iss_pipeline(entity) : &video->pipe;
> pipe->external = NULL;
> - pipe->external_rate = 0;
> + pipe->external_lfreq = 0;
> pipe->external_bpp = 0;
>
> ret = media_entity_enum_init(&pipe->ent_enum, entity->graph_obj.mdev);
> diff --git a/drivers/staging/media/omap4iss/iss_video.h b/drivers/staging/media/omap4iss/iss_video.h
> index 526281bf0051..2ad5c8483958 100644
> --- a/drivers/staging/media/omap4iss/iss_video.h
> +++ b/drivers/staging/media/omap4iss/iss_video.h
> @@ -86,7 +86,7 @@ struct iss_pipeline {
> bool error;
> struct v4l2_fract max_timeperframe;
> struct v4l2_subdev *external;
> - unsigned int external_rate;
> + s64 external_lfreq;
> int external_bpp;
> };
>
--
Sakari Ailus
