Re: [PATCH] drm/msm: populate intf_audio_select() base on hardware capability

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On 12/02/2022 02:23, Kuogee Hsieh wrote:
> intf_audio_select() callback function use to configure
> HDMI_DP_CORE_SELECT to decide audio output routes to HDMI or DP
> interface. HDMI is obsoleted at newer chipset. To keep supporting
> legacy hdmi application, intf_audio_select call back function have
> to be populated base on hardware chip capability where legacy
> chipsets have has_audio_select flag set to true.

So, after thinking more about the patch, I have a bunch of questions:

You are enabling this callback only for sdm845 and sm8150.

Does this register exist on other (newer) platforms (but just defaults 
to DP)?

Neither sdm845 nor sm8150 support INTF_HDMI. What's the purpose of the 
register on these platforms?

Does that mean that we should program the register for HDMI (e.g. on 8998)?

And, as you are touching this piece of code, how do we control audio 
routing on newer platforms which have several hardware DP interfaces?


> 
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c | 2 ++
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h | 1 +
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_top.c     | 9 ++++++---
>   3 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> index 272b14b..23680e7 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c
> @@ -201,6 +201,7 @@ static const struct dpu_caps sdm845_dpu_caps = {
>   	.has_dim_layer = true,
>   	.has_idle_pc = true,
>   	.has_3d_merge = true,
> +	.has_audio_select = true,
>   	.max_linewidth = DEFAULT_DPU_OUTPUT_LINE_WIDTH,
>   	.pixel_ram_size = DEFAULT_PIXEL_RAM_SIZE,
>   	.max_hdeci_exp = MAX_HORZ_DECIMATION,
> @@ -229,6 +230,7 @@ static const struct dpu_caps sm8150_dpu_caps = {
>   	.has_dim_layer = true,
>   	.has_idle_pc = true,
>   	.has_3d_merge = true,
> +	.has_audio_select = true,
>   	.max_linewidth = 4096,
>   	.pixel_ram_size = DEFAULT_PIXEL_RAM_SIZE,
>   	.max_hdeci_exp = MAX_HORZ_DECIMATION,
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
> index e5a96d6..b33f91b 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
> @@ -357,6 +357,7 @@ struct dpu_caps {
>   	bool has_dim_layer;
>   	bool has_idle_pc;
>   	bool has_3d_merge;
> +	bool has_audio_select;
>   	/* SSPP limits */
>   	u32 max_linewidth;
>   	u32 pixel_ram_size;
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_top.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_top.c
> index 282e3c6..e608f4d 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_top.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_top.c
> @@ -261,14 +261,17 @@ static void dpu_hw_intf_audio_select(struct dpu_hw_mdp *mdp)
>   }
>   
>   static void _setup_mdp_ops(struct dpu_hw_mdp_ops *ops,
> -		unsigned long cap)
> +		unsigned long cap,
> +		const struct dpu_mdss_cfg *m)
>   {
>   	ops->setup_split_pipe = dpu_hw_setup_split_pipe;
>   	ops->setup_clk_force_ctrl = dpu_hw_setup_clk_force_ctrl;
>   	ops->get_danger_status = dpu_hw_get_danger_status;
>   	ops->setup_vsync_source = dpu_hw_setup_vsync_source;
>   	ops->get_safe_status = dpu_hw_get_safe_status;
> -	ops->intf_audio_select = dpu_hw_intf_audio_select;
> +
> +	if (m->caps->has_audio_select)
> +		ops->intf_audio_select = dpu_hw_intf_audio_select;
>   }
>   
>   static const struct dpu_mdp_cfg *_top_offset(enum dpu_mdp mdp,
> @@ -320,7 +323,7 @@ struct dpu_hw_mdp *dpu_hw_mdptop_init(enum dpu_mdp idx,
>   	 */
>   	mdp->idx = idx;
>   	mdp->caps = cfg;
> -	_setup_mdp_ops(&mdp->ops, mdp->caps->features);
> +	_setup_mdp_ops(&mdp->ops, mdp->caps->features, m);
>   
>   	return mdp;
>   }


-- 
With best wishes
Dmitry