linux-kernel - Re: [PATCH v2 06/11] drm/msm/disp/dpu1: Don't use DSC with mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Thu, 14 Oct 2021 16:41:50 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Vinod Koul <vkoul@...nel.org>, Rob Clark <robdclark@...il.com>
Cc:     linux-arm-msm@...r.kernel.org,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Jonathan Marek <jonathan@...ek.ca>,
        Abhinav Kumar <abhinavk@...eaurora.org>,
        Jeffrey Hugo <jeffrey.l.hugo@...il.com>,
        Sumit Semwal <sumit.semwal@...aro.org>,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        freedreno@...ts.freedesktop.org
Subject: Re: [PATCH v2 06/11] drm/msm/disp/dpu1: Don't use DSC with mode_3d

On 07/10/2021 10:08, Vinod Koul wrote:
> We cannot enable mode_3d when we are using the DSC. So pass
> configuration to detect DSC is enabled and not enable mode_3d
> when we are using DSC
> 
> We add a helper dpu_encoder_helper_get_dsc_mode() to detect dsc
> enabled and pass this to .setup_intf_cfg()
> 
> Signed-off-by: Vinod Koul <vkoul@...nel.org>
> ---
> Changes since
> v1:
>   - Move this patch from 7 to 6
>   - Update the changelog
>   - Make dsc as int and store the DSC indices
> 
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h     | 11 +++++++++++
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c |  2 ++
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c           |  5 +++--
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h           |  2 ++
>   4 files changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> index e7270eb6b84b..fca07ed03317 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> @@ -332,6 +332,17 @@ static inline enum dpu_3d_blend_mode dpu_encoder_helper_get_3d_blend_mode(
>   	return BLEND_3D_NONE;
>   }
>   
> +static inline bool dpu_encoder_helper_get_dsc_mode(struct dpu_encoder_phys *phys_enc)
> +{
> +	struct drm_encoder *drm_enc = phys_enc->parent;
> +	struct msm_drm_private *priv = drm_enc->dev->dev_private;
> +
> +	if (priv->dsc)
> +		return BIT(0) | BIT(1); /* Hardcoding for 2 DSC topology */

Please use defined values here rater than just BIT().

> +
> +	return 0;
> +}
> +
>   /**
>    * dpu_encoder_helper_split_config - split display configuration helper function
>    *	This helper function may be used by physical encoders to configure
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> index aa01698d6b25..8e5c0911734c 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> @@ -70,6 +70,8 @@ static void _dpu_encoder_phys_cmd_update_intf_cfg(
>   	intf_cfg.intf_mode_sel = DPU_CTL_MODE_SEL_CMD;
>   	intf_cfg.stream_sel = cmd_enc->stream_sel;
>   	intf_cfg.mode_3d = dpu_encoder_helper_get_3d_blend_mode(phys_enc);
> +	intf_cfg.dsc = dpu_encoder_helper_get_dsc_mode(phys_enc);
> +
>   	ctl->ops.setup_intf_cfg(ctl, &intf_cfg);
>   }
>   
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> index 64740ddb983e..3c79bd9c2fe5 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> @@ -118,7 +118,7 @@ static u32 dpu_hw_ctl_get_pending_flush(struct dpu_hw_ctl *ctx)
>   	return ctx->pending_flush_mask;
>   }
>   
> -static inline void dpu_hw_ctl_trigger_flush_v1(struct dpu_hw_ctl *ctx)
> +static void dpu_hw_ctl_trigger_flush_v1(struct dpu_hw_ctl *ctx)
>   {
>   
>   	if (ctx->pending_flush_mask & BIT(MERGE_3D_IDX))
> @@ -519,7 +519,8 @@ static void dpu_hw_ctl_intf_cfg(struct dpu_hw_ctl *ctx,
>   
>   	intf_cfg |= (cfg->intf & 0xF) << 4;
>   
> -	if (cfg->mode_3d) {
> +	/* In DSC we can't set merge, so check for dsc too */
> +	if (cfg->mode_3d && !cfg->dsc) {

The more I think about this hunk, the more I'm unsure about it.
Downstream has the following topoligies defined:
  * @SDE_RM_TOPOLOGY_DUALPIPE_3DMERGE_DSC: 2 LM, 2 PP, 3DMux, 1 DSC, 1 
INTF/WB
  * @SDE_RM_TOPOLOGY_QUADPIPE_3DMERGE_DSC  4 LM, 4 PP, 3DMux, 3 DSC, 2 INTF

While the latter is not supported on sdm845, the former one should be 
(by the hardware). So in the driver I think we should make sure that 
mode_3d does not get set rather than disallowing it here.

>   		intf_cfg |= BIT(19);
>   		intf_cfg |= (cfg->mode_3d - 0x1) << 20;
>   	}
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> index 806c171e5df2..5dfac5994bd4 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> @@ -39,6 +39,7 @@ struct dpu_hw_stage_cfg {
>    * @mode_3d:               3d mux configuration
>    * @merge_3d:              3d merge block used
>    * @intf_mode_sel:         Interface mode, cmd / vid
> + * @dsc:                   DSC BIT masks
>    * @stream_sel:            Stream selection for multi-stream interfaces
>    */
>   struct dpu_hw_intf_cfg {
> @@ -46,6 +47,7 @@ struct dpu_hw_intf_cfg {
>   	enum dpu_3d_blend_mode mode_3d;
>   	enum dpu_merge_3d merge_3d;
>   	enum dpu_ctl_mode_sel intf_mode_sel;
> +	unsigned int dsc;
>   	int stream_sel;
>   };
>   
> 


-- 
With best wishes
Dmitry