Re: [PATCH v4 07/25] drm/msm/dpu: move resource allocation to CRTC

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

On 12/16/2024 4:43 PM, Jessica Zhang wrote:
> From: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
>
> All resource allocation is centered around the LMs. Then other blocks
> (except DSCs) are allocated basing on the LMs that was selected, and LM
> powers up the CRTC rather than the encoder.
>
> Moreover if at some point the driver supports encoder cloning,
> allocating resources from the encoder will be incorrect, as all clones
> will have different encoder IDs, while LMs are to be shared by these
> encoders.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> [quic_abhinavk@xxxxxxxxxxx: Refactored resource allocation for CDM]
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> [quic_jesszhan@xxxxxxxxxxx: Changed to grabbing exising global state]
> Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  86 ++++++++++
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 256 ++++++++++------------------
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h |   8 +
>   3 files changed, 181 insertions(+), 169 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 9f6ffd344693ecfb633095772a31ada5613345dc..186ed84f59f16997716fe216e635b8dce07a63a1 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -1182,6 +1182,78 @@ static bool dpu_crtc_needs_dirtyfb(struct drm_crtc_state *cstate)
>   	return false;
>   }
>   

<snip>

> +static bool dpu_encoder_needs_dsc_merge(struct drm_encoder *drm_enc)
>   {
> -	struct dpu_crtc_state *cstate;
> -	struct dpu_hw_blk *hw_ctl[MAX_CHANNELS_PER_ENC];
> -	struct dpu_hw_blk *hw_lm[MAX_CHANNELS_PER_ENC];
> -	struct dpu_hw_blk *hw_dspp[MAX_CHANNELS_PER_ENC];
> -	int num_lm, num_ctl, num_dspp, i;
> -
> -	cstate = to_dpu_crtc_state(crtc_state);
> -
> -	memset(cstate->mixers, 0, sizeof(cstate->mixers));
> -
> -	num_ctl = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
> -		drm_enc->crtc, DPU_HW_BLK_CTL, hw_ctl, ARRAY_SIZE(hw_ctl));
> -	num_lm = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
> -		drm_enc->crtc, DPU_HW_BLK_LM, hw_lm, ARRAY_SIZE(hw_lm));
> -	num_dspp = dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
> -		drm_enc->crtc, DPU_HW_BLK_DSPP, hw_dspp,
> -		ARRAY_SIZE(hw_dspp));
> +	struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
> +	u32 num_intf = 0;
> +	u32 num_dsc = 0;
> +	int i;
>   
> -	for (i = 0; i < num_lm; i++) {
> -		int ctl_idx = (i < num_ctl) ? i : (num_ctl-1);
> +	for (i = 0; i < MAX_PHYS_ENCODERS_PER_VIRTUAL; i++)
> +		if (dpu_enc->phys_encs[i])
> +			num_intf++;
>   
> -		cstate->mixers[i].hw_lm = to_dpu_hw_mixer(hw_lm[i]);
> -		cstate->mixers[i].lm_ctl = to_dpu_hw_ctl(hw_ctl[ctl_idx]);
> -		cstate->mixers[i].hw_dspp = i < num_dspp ? to_dpu_hw_dspp(hw_dspp[i]) : NULL;
> -	}
> +	/* We only support 2 DSC mode (with 2 LM and 1 INTF) */
> +	if (dpu_enc->dsc)
> +		num_dsc += 2;
>   

As we requested in v3, can you please explain why we have num_dsc +=2 
instead of just num_dsc = 2? If we are hard-coding 2:2:1, this should be 
just num_dsc = 2.