Re: [PATCH v2 14/16] drm/msm/dpu: reserve cdm blocks for writeback in case of YUV output

[Dmitry Baryshkov]

On Fri, 8 Dec 2023 at 07:07, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
>
> Reserve CDM blocks for writeback if the format of the output fb
> is YUV. At the moment, the reservation is done only for writeback
> but can easily be extended by relaxing the checks once other
> interfaces are ready to output YUV.
>
> changes in v2:
>         - use needs_cdm from topology struct
>         - drop fb related checks from atomic_mode_set()

It looks like this should be squashed with the patch 11. The 'unbind
CDM' doesn't really make sense without this patch. We need to allocate
it first,  before touching it.

>
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 27 +++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 862912727925..a576e3e62429 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -16,6 +16,7 @@
>  #include <drm/drm_crtc.h>
>  #include <drm/drm_file.h>
>  #include <drm/drm_probe_helper.h>
> +#include <drm/drm_framebuffer.h>
>
>  #include "msm_drv.h"
>  #include "dpu_kms.h"
> @@ -583,6 +584,7 @@ static int dpu_encoder_virt_atomic_check(
>         struct drm_display_mode *adj_mode;
>         struct msm_display_topology topology;
>         struct dpu_global_state *global_state;
> +       struct drm_framebuffer *fb;
>         struct drm_dsc_config *dsc;
>         int i = 0;
>         int ret = 0;
> @@ -623,6 +625,22 @@ static int dpu_encoder_virt_atomic_check(
>
>         topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode, crtc_state, dsc);
>
> +       /*
> +        * Use CDM only for writeback at the moment as other interfaces cannot handle it.
> +        * if writeback itself cannot handle cdm for some reason it will fail in its atomic_check()
> +        * earlier.
> +        */
> +       if (dpu_enc->disp_info.intf_type == INTF_WB && conn_state->writeback_job) {
> +               fb = conn_state->writeback_job->fb;
> +
> +               if (fb && DPU_FORMAT_IS_YUV(to_dpu_format(msm_framebuffer_format(fb))))
> +                       topology.needs_cdm = true;
> +               if (topology.needs_cdm && !dpu_enc->cur_master->hw_cdm)
> +                       crtc_state->mode_changed = true;
> +               else if (!topology.needs_cdm && dpu_enc->cur_master->hw_cdm)
> +                       crtc_state->mode_changed = true;
> +       }
> +
>         /*
>          * Release and Allocate resources on every modeset
>          * Dont allocate when active is false.
> @@ -1063,6 +1081,15 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
>
>         dpu_enc->dsc_mask = dsc_mask;
>
> +       if (dpu_enc->disp_info.intf_type == INTF_WB && conn_state->writeback_job) {
> +               struct dpu_hw_blk *hw_cdm = NULL;
> +
> +               dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
> +                                             drm_enc->base.id, DPU_HW_BLK_CDM,
> +                                             &hw_cdm, 1);
> +               dpu_enc->cur_master->hw_cdm = hw_cdm ? to_dpu_hw_cdm(hw_cdm) : NULL;
> +       }
> +
>         cstate = to_dpu_crtc_state(crtc_state);
>
>         for (i = 0; i < num_lm; i++) {
> --
> 2.40.1
>


--
With best wishes

Dmitry