Re: [PATCH v3 6/6] drm/msm/dsi: support DSC configurations with slice_per_pkt > 1

[Dmitry Baryshkov]

On Wed, 3 Apr 2024 at 12:11, Jun Nie <jun.nie@xxxxxxxxxx> wrote:
>
> From: Jonathan Marek <jonathan@xxxxxxxx>
>
> Support slice_per_pkt in msm driver.
>
> Note that the removed "pkt_per_line = slice_per_intf * slice_per_pkt"
> comment is incorrect.
>
> Also trim the code to simplify the dsc reference.
>
> Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
> Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/dsi/dsi_host.c | 35 ++++++++++++++---------------------
>  1 file changed, 14 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index b0507a42ee6a..0c6f40dbd25c 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -866,17 +866,10 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
>         slice_per_intf = msm_dsc_get_slices_per_intf(dsc, hdisplay);
>
>         total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;
> -       bytes_per_pkt = dsc->slice_chunk_size; /* * slice_per_pkt; */
> -
> +       bytes_per_pkt = dsc->slice_chunk_size * dsc->slice_per_pkt;

Please don't mix cleanup and functional changes.

>         eol_byte_num = total_bytes_per_intf % 3;
>
> -       /*
> -        * Typically, pkt_per_line = slice_per_intf * slice_per_pkt.
> -        *
> -        * Since the current driver only supports slice_per_pkt = 1,
> -        * pkt_per_line will be equal to slice per intf for now.
> -        */
> -       pkt_per_line = slice_per_intf;
> +       pkt_per_line = slice_per_intf / dsc->slice_per_pkt;
>
>         if (is_cmd_mode) /* packet data type */
>                 reg = DSI_COMMAND_COMPRESSION_MODE_CTRL_STREAM0_DATATYPE(MIPI_DSI_DCS_LONG_WRITE);
> @@ -916,6 +909,7 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
>  static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>  {
>         struct drm_display_mode *mode = msm_host->mode;
> +       struct drm_dsc_config *dsc = msm_host->dsc;

And here too. Please pull msm_host->dsc change to a separate patch.

>         u32 hs_start = 0, vs_start = 0; /* take sync start as 0 */
>         u32 h_total = mode->htotal;
>         u32 v_total = mode->vtotal;
> @@ -947,8 +941,7 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>                 hdisplay /= 2;
>         }
>
> -       if (msm_host->dsc) {
> -               struct drm_dsc_config *dsc = msm_host->dsc;
> +       if (dsc) {
>                 u32 bytes_per_pclk;
>
>                 /* update dsc params with timing params */
> @@ -988,14 +981,14 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>                 else
>                         bytes_per_pclk = 3;
>
> -               hdisplay = DIV_ROUND_UP(msm_dsc_get_bytes_per_line(msm_host->dsc), bytes_per_pclk);
> +               hdisplay = DIV_ROUND_UP(msm_dsc_get_bytes_per_line(dsc), bytes_per_pclk);
>
>                 h_total += hdisplay;
>                 ha_end = ha_start + hdisplay;
>         }
>
>         if (msm_host->mode_flags & MIPI_DSI_MODE_VIDEO) {
> -               if (msm_host->dsc)
> +               if (dsc)
>                         dsi_update_dsc_timing(msm_host, false, mode->hdisplay);
>
>                 dsi_write(msm_host, REG_DSI_ACTIVE_H,
> @@ -1016,21 +1009,17 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>                         DSI_ACTIVE_VSYNC_VPOS_START(vs_start) |
>                         DSI_ACTIVE_VSYNC_VPOS_END(vs_end));
>         } else {                /* command mode */
> -               if (msm_host->dsc)
> +               if (dsc)
>                         dsi_update_dsc_timing(msm_host, true, mode->hdisplay);
>
>                 /* image data and 1 byte write_memory_start cmd */
> -               if (!msm_host->dsc)
> +               if (!dsc)
>                         wc = hdisplay * mipi_dsi_pixel_format_to_bpp(msm_host->format) / 8 + 1;
>                 else
>                         /*
>                          * When DSC is enabled, WC = slice_chunk_size * slice_per_pkt + 1.
> -                        * Currently, the driver only supports default value of slice_per_pkt = 1
> -                        *
> -                        * TODO: Expand mipi_dsi_device struct to hold slice_per_pkt info
> -                        *       and adjust DSC math to account for slice_per_pkt.
>                          */
> -                       wc = msm_host->dsc->slice_chunk_size + 1;
> +                       wc = dsc->slice_chunk_size * dsc->slice_per_pkt + 1;
>
>                 dsi_write(msm_host, REG_DSI_CMD_MDP_STREAM0_CTRL,
>                         DSI_CMD_MDP_STREAM0_CTRL_WORD_COUNT(wc) |
> @@ -1657,8 +1646,12 @@ static int dsi_host_attach(struct mipi_dsi_host *host,
>         msm_host->lanes = dsi->lanes;
>         msm_host->format = dsi->format;
>         msm_host->mode_flags = dsi->mode_flags;
> -       if (dsi->dsc)
> +       if (dsi->dsc) {
>                 msm_host->dsc = dsi->dsc;
> +               /* for backwards compatibility, assume 1 if not set */
> +               if (!dsi->dsc->slice_per_pkt)
> +                       dsi->dsc->slice_per_pkt = 1;
> +       }
>
>         /* Some gpios defined in panel DT need to be controlled by host */
>         ret = dsi_host_init_panel_gpios(msm_host, &dsi->dev);
>
> --
> 2.34.1
>


-- 
With best wishes
Dmitry