Message-ID: <ae600a78-aa7f-9c9e-949b-0e946869a032@quicinc.com>
Date:   Mon, 6 Dec 2021 10:54:34 -0800
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Subject: Re: [PATCH v5] drm/msm/dp: employ bridge mechanism for display enable
 and disable
Content-Language: en-US
To:     Kuogee Hsieh <quic_khsieh@quicinc.com>, <robdclark@gmail.com>,
        <sean@poorly.run>, <swboyd@chromium.org>, <vkoul@kernel.org>,
        <daniel@ffwll.ch>, <airlied@linux.ie>, <agross@kernel.org>,
        <dmitry.baryshkov@linaro.org>, <bjorn.andersson@linaro.org>
CC:     <aravindh@codeaurora.org>, <freedreno@lists.freedesktop.org>,
        <dri-devel@lists.freedesktop.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <1638205444-4616-1-git-send-email-quic_khsieh@quicinc.com>
From:   Abhinav Kumar <quic_abhinavk@quicinc.com>
In-Reply-To: <1638205444-4616-1-git-send-email-quic_khsieh@quicinc.com>
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On 11/29/2021 9:04 AM, Kuogee Hsieh wrote:
> Currently the msm_dp_*** functions implement the same sequence which would
> happen when drm_bridge is used. hence get rid of this intermediate layer
> and align with the drm_bridge usage to avoid customized implementation.
> 
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> 
> Changes in v2:
> -- revise commit text
> -- rename dp_bridge to msm_dp_bridge
> -- delete empty functions
> 
> Changes in v3:
> -- replace kzalloc() with devm_kzalloc()
> -- replace __dp_display_enable() with dp_display_enable()
> -- replace __dp_display_disable() with dp_display_disable()
> 
> Changes in v4:
> -- msm_dp_bridge_init() called from msm_dp_modeset_init() same as dsi
> 
> Changes in v5:
> -- delete attach, mode_fixup and pre_enable from dp_bridge_ops
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 21 --------
>   drivers/gpu/drm/msm/dp/dp_display.c         | 16 +++++-
>   drivers/gpu/drm/msm/dp/dp_display.h         |  1 +
>   drivers/gpu/drm/msm/dp/dp_drm.c             | 77 +++++++++++++++++++++++++++++
>   drivers/gpu/drm/msm/msm_drv.h               | 12 +++--
>   5 files changed, 100 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 31050aa..c4e08c4 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -1003,9 +1003,6 @@ static void dpu_encoder_virt_mode_set(struct drm_encoder *drm_enc,
>   
>   	trace_dpu_enc_mode_set(DRMID(drm_enc));
>   
> -	if (drm_enc->encoder_type == DRM_MODE_ENCODER_TMDS)
> -		msm_dp_display_mode_set(dpu_enc->dp, drm_enc, mode, adj_mode);
> -
>   	list_for_each_entry(conn_iter, connector_list, head)
>   		if (conn_iter->encoder == drm_enc)
>   			conn = conn_iter;
> @@ -1181,14 +1178,6 @@ static void dpu_encoder_virt_enable(struct drm_encoder *drm_enc)
>   
>   	_dpu_encoder_virt_enable_helper(drm_enc);
>   
> -	if (drm_enc->encoder_type == DRM_MODE_ENCODER_TMDS) {
> -		ret = msm_dp_display_enable(dpu_enc->dp, drm_enc);
> -		if (ret) {
> -			DPU_ERROR_ENC(dpu_enc, "dp display enable failed: %d\n",
> -				ret);
> -			goto out;
> -		}
> -	}
>   	dpu_enc->enabled = true;
>   
>   out:
> @@ -1214,11 +1203,6 @@ static void dpu_encoder_virt_disable(struct drm_encoder *drm_enc)
>   	/* wait for idle */
>   	dpu_encoder_wait_for_event(drm_enc, MSM_ENC_TX_COMPLETE);
>   
> -	if (drm_enc->encoder_type == DRM_MODE_ENCODER_TMDS) {
> -		if (msm_dp_display_pre_disable(dpu_enc->dp, drm_enc))
> -			DPU_ERROR_ENC(dpu_enc, "dp display push idle failed\n");
> -	}
> -
>   	dpu_encoder_resource_control(drm_enc, DPU_ENC_RC_EVENT_PRE_STOP);
>   
>   	for (i = 0; i < dpu_enc->num_phys_encs; i++) {
> @@ -1243,11 +1227,6 @@ static void dpu_encoder_virt_disable(struct drm_encoder *drm_enc)
>   
>   	DPU_DEBUG_ENC(dpu_enc, "encoder disabled\n");
>   
> -	if (drm_enc->encoder_type == DRM_MODE_ENCODER_TMDS) {
> -		if (msm_dp_display_disable(dpu_enc->dp, drm_enc))
> -			DPU_ERROR_ENC(dpu_enc, "dp display disable failed\n");
> -	}
> -
>   	mutex_unlock(&dpu_enc->enc_lock);
>   }
>   
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 2f113ff..89a8d43 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -1571,6 +1571,18 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
>   	}
>   
>   	priv->connectors[priv->num_connectors++] = dp_display->connector;
> +
> +	dp_display->bridge = msm_dp_bridge_init(dp_display, dev, encoder);
> +	if (IS_ERR(dp_display->bridge)) {
> +		ret = PTR_ERR(dp_display->bridge);
> +		DRM_DEV_ERROR(dev->dev,
> +			"failed to create dp bridge: %d\n", ret);
> +		dp_display->bridge = NULL;
> +		return ret;
> +	}
> +
> +	priv->bridges[priv->num_bridges++] = dp_display->bridge;
> +
>   	return 0;
>   }
>   
> @@ -1674,8 +1686,8 @@ int msm_dp_display_disable(struct msm_dp *dp, struct drm_encoder *encoder)
>   }
>   
>   void msm_dp_display_mode_set(struct msm_dp *dp, struct drm_encoder *encoder,
> -				struct drm_display_mode *mode,
> -				struct drm_display_mode *adjusted_mode)
> +				const struct drm_display_mode *mode,
> +				const struct drm_display_mode *adjusted_mode)
>   {
>   	struct dp_display_private *dp_display;
>   
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
> index 76f45f9..2237e80 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -13,6 +13,7 @@
>   struct msm_dp {
>   	struct drm_device *drm_dev;
>   	struct device *codec_dev;
> +	struct drm_bridge *bridge;
>   	struct drm_connector *connector;
>   	struct drm_encoder *encoder;
>   	struct drm_panel *drm_panel;
> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
> index f33e315..15c0309e 100644
> --- a/drivers/gpu/drm/msm/dp/dp_drm.c
> +++ b/drivers/gpu/drm/msm/dp/dp_drm.c
> @@ -5,12 +5,21 @@
>   
>   #include <drm/drm_atomic_helper.h>
>   #include <drm/drm_atomic.h>
> +#include <drm/drm_bridge.h>
>   #include <drm/drm_crtc.h>
>   
>   #include "msm_drv.h"
>   #include "msm_kms.h"
>   #include "dp_drm.h"
>   
> +
> +struct msm_dp_bridge {
> +	struct drm_bridge bridge;
> +	struct msm_dp *dp_display;
> +};
> +
> +#define to_dp_display(x)     container_of((x), struct msm_dp_bridge, bridge)
> +
>   struct dp_connector {
>   	struct drm_connector base;
>   	struct msm_dp *dp_display;
> @@ -162,3 +171,71 @@ struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display)
>   
>   	return connector;
>   }
> +
> +static void dp_bridge_mode_set(struct drm_bridge *drm_bridge,
> +				const struct drm_display_mode *mode,
> +				const struct drm_display_mode *adjusted_mode)
> +{
> +	struct msm_dp_bridge *dp_bridge = to_dp_display(drm_bridge);
> +	struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> +	msm_dp_display_mode_set(dp_display, drm_bridge->encoder, mode, adjusted_mode);
> +}
> +
> +static void dp_bridge_enable(struct drm_bridge *drm_bridge)
> +{
> +	struct msm_dp_bridge *dp_bridge = to_dp_display(drm_bridge);
> +	struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> +	msm_dp_display_enable(dp_display, drm_bridge->encoder);
> +}
> +
> +static void dp_bridge_disable(struct drm_bridge *drm_bridge)
> +{
> +	struct msm_dp_bridge *dp_bridge = to_dp_display(drm_bridge);
> +	struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> +	msm_dp_display_pre_disable(dp_display, drm_bridge->encoder);
> +}
> +
> +static void dp_bridge_post_disable(struct drm_bridge *drm_bridge)
> +{
> +	struct msm_dp_bridge *dp_bridge = to_dp_display(drm_bridge);
> +	struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> +	msm_dp_display_disable(dp_display, drm_bridge->encoder);
> +}
> +
> +static const struct drm_bridge_funcs dp_bridge_ops = {
> +	.enable       = dp_bridge_enable,
> +	.disable      = dp_bridge_disable,
> +	.post_disable = dp_bridge_post_disable,
> +	.mode_set     = dp_bridge_mode_set,
> +};
> +
> +struct drm_bridge *msm_dp_bridge_init(struct msm_dp *dp_display, struct drm_device *dev,
> +			struct drm_encoder *encoder)
> +{
> +	int rc;
> +	struct msm_dp_bridge *dp_bridge;
> +	struct drm_bridge *bridge;
> +
> +	dp_bridge = devm_kzalloc(dev->dev, sizeof(*dp_bridge), GFP_KERNEL);
> +	if (!dp_bridge)
> +		return ERR_PTR(-ENOMEM);
> +
> +	dp_bridge->dp_display = dp_display;
> +
> +	bridge = &dp_bridge->bridge;
> +	bridge->funcs = &dp_bridge_ops;
> +	bridge->encoder = encoder;
> +
> +	rc = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> +	if (rc) {
> +		DRM_ERROR("failed to attach bridge, rc=%d\n", rc);
> +		kfree(dp_bridge);
> +		return ERR_PTR(rc);
> +	}
> +
> +	return bridge;
> +}
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index 4bb797e..c18a959 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -388,8 +388,12 @@ int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder);
>   int msm_dp_display_disable(struct msm_dp *dp, struct drm_encoder *encoder);
>   int msm_dp_display_pre_disable(struct msm_dp *dp, struct drm_encoder *encoder);
>   void msm_dp_display_mode_set(struct msm_dp *dp, struct drm_encoder *encoder,
> -				struct drm_display_mode *mode,
> -				struct drm_display_mode *adjusted_mode);
> +				const struct drm_display_mode *mode,
> +				const struct drm_display_mode *adjusted_mode);
> +
> +struct drm_bridge *msm_dp_bridge_init(struct msm_dp *dp_display,
> +					struct drm_device *dev,
> +					struct drm_encoder *encoder);
>   void msm_dp_irq_postinstall(struct msm_dp *dp_display);
>   void msm_dp_snapshot(struct msm_disp_state *disp_state, struct msm_dp *dp_display);
>   
> @@ -426,8 +430,8 @@ static inline int msm_dp_display_pre_disable(struct msm_dp *dp,
>   }
>   static inline void msm_dp_display_mode_set(struct msm_dp *dp,
>   				struct drm_encoder *encoder,
> -				struct drm_display_mode *mode,
> -				struct drm_display_mode *adjusted_mode)
> +				const struct drm_display_mode *mode,
> +				const struct drm_display_mode *adjusted_mode)
>   {
>   }
>   
>