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Message-ID: <b16ca5b1-7f4a-17ef-8cd1-f2b059a92624@quicinc.com>
Date:   Thu, 8 Dec 2022 15:14:51 -0800
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Subject: Re: [PATCH v5 08/12] drm/msm/dp: Rely on hpd_enable/disable callbacks
Content-Language: en-US
To:     Bjorn Andersson <quic_bjorande@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
CC:     Rob Clark <robdclark@gmail.com>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Kalyan Thota <quic_kalyant@quicinc.com>,
        Jessica Zhang <quic_jesszhan@quicinc.com>,
        "Johan Hovold" <johan+linaro@kernel.org>,
        Sankeerth Billakanti <quic_sbillaka@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
        <freedreno@lists.freedesktop.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20221207220012.16529-1-quic_bjorande@quicinc.com>
 <20221207220012.16529-9-quic_bjorande@quicinc.com>
From:   Kuogee Hsieh <quic_khsieh@quicinc.com>
In-Reply-To: <20221207220012.16529-9-quic_bjorande@quicinc.com>
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On 12/7/2022 2:00 PM, Bjorn Andersson wrote:
> From: Bjorn Andersson <bjorn.andersson@linaro.org>
>
> The DisplayPort controller's internal HPD interrupt handling is used for
> cases where the HPD signal is connected to a GPIO which is pinmuxed into
> the DisplayPort controller. In other configurations the HPD notification
> might be delivered by the DRM framework from an associated bridge.
>
> This difference is not appropriately represented by the "is_edp"
> boolean, but is properly represented by the frameworks invocation of the
> hpd_enable() and hpd_disable() callbacks. Switch the current condition
> to rely on these callbacks instead.
>
> This ensures appropriate handling of the three cases; no bridge
> connected, a bridge without DRM_BRIDGE_OP_HPD and a bridge with
> DRM_BRIDGE_OP_HPD.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---
>
> Changes since v4:
> - Reordered the hpd_enable/disable patch earlier
> - Squashed in internal_hpd conditional changes into the same patch
>
>   drivers/gpu/drm/msm/dp/dp_display.c | 40 +++++++++++++++++++++--------
>   drivers/gpu/drm/msm/dp/dp_display.h |  1 +
>   drivers/gpu/drm/msm/dp/dp_drm.c     |  2 ++
>   drivers/gpu/drm/msm/dp/dp_drm.h     |  2 ++
>   4 files changed, 35 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 666b45c8ab80..095adf528e43 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -610,8 +610,10 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
>   	}
>   
>   	/* enable HDP irq_hpd/replug interrupt */
> -	dp_catalog_hpd_config_intr(dp->catalog,
> -		DP_DP_IRQ_HPD_INT_MASK | DP_DP_HPD_REPLUG_INT_MASK, true);
> +	if (dp->dp_display.internal_hpd)
> +		dp_catalog_hpd_config_intr(dp->catalog,
> +					   DP_DP_IRQ_HPD_INT_MASK | DP_DP_HPD_REPLUG_INT_MASK,
> +					   true);
>   
>   	drm_dbg_dp(dp->drm_dev, "After, type=%d hpd_state=%d\n",
>   			dp->dp_display.connector_type, state);
> @@ -651,8 +653,10 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
>   			dp->dp_display.connector_type, state);
>   
>   	/* disable irq_hpd/replug interrupts */
> -	dp_catalog_hpd_config_intr(dp->catalog,
> -		DP_DP_IRQ_HPD_INT_MASK | DP_DP_HPD_REPLUG_INT_MASK, false);
> +	if (dp->dp_display.internal_hpd)
> +		dp_catalog_hpd_config_intr(dp->catalog,
> +					   DP_DP_IRQ_HPD_INT_MASK | DP_DP_HPD_REPLUG_INT_MASK,
> +					   false);
>   
>   	/* unplugged, no more irq_hpd handle */
>   	dp_del_event(dp, EV_IRQ_HPD_INT);
> @@ -678,7 +682,8 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
>   	}
>   
>   	/* disable HPD plug interrupts */
> -	dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_PLUG_INT_MASK, false);
> +	if (dp->dp_display.internal_hpd)
> +		dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_PLUG_INT_MASK, false);
>   
>   	/*
>   	 * We don't need separate work for disconnect as
> @@ -696,7 +701,7 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
>   	dp_display_handle_plugged_change(&dp->dp_display, false);
>   
>   	/* enable HDP plug interrupt to prepare for next plugin */
> -	if (!dp->dp_display.is_edp)
> +	if (dp->dp_display.internal_hpd)
>   		dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_PLUG_INT_MASK, true);
>   
>   	drm_dbg_dp(dp->drm_dev, "After, type=%d hpd_state=%d\n",
> @@ -1081,8 +1086,8 @@ static void dp_display_config_hpd(struct dp_display_private *dp)
>   	dp_display_host_init(dp);
>   	dp_catalog_ctrl_hpd_config(dp->catalog);
>   
> -	/* Enable plug and unplug interrupts only for external DisplayPort */
> -	if (!dp->dp_display.is_edp)
> +	/* Enable plug and unplug interrupts only if requested */
> +	if (dp->dp_display.internal_hpd)
>   		dp_catalog_hpd_config_intr(dp->catalog,
>   				DP_DP_HPD_PLUG_INT_MASK |
>   				DP_DP_HPD_UNPLUG_INT_MASK,
> @@ -1374,8 +1379,7 @@ static int dp_pm_resume(struct device *dev)
>   
>   	dp_catalog_ctrl_hpd_config(dp->catalog);
>   
> -
> -	if (!dp->dp_display.is_edp)
> +	if (dp->dp_display.internal_hpd)
>   		dp_catalog_hpd_config_intr(dp->catalog,
>   				DP_DP_HPD_PLUG_INT_MASK |
>   				DP_DP_HPD_UNPLUG_INT_MASK,
> @@ -1772,3 +1776,19 @@ void dp_bridge_mode_set(struct drm_bridge *drm_bridge,
>   	dp_display->dp_mode.h_active_low =
>   		!!(dp_display->dp_mode.drm_mode.flags & DRM_MODE_FLAG_NHSYNC);
>   }
> +
> +void dp_bridge_hpd_enable(struct drm_bridge *bridge)
> +{
> +	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
> +	struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> +	dp_display->internal_hpd = true;
> +}
> +
> +void dp_bridge_hpd_disable(struct drm_bridge *bridge)
> +{
> +	struct msm_dp_bridge *dp_bridge = to_dp_bridge(bridge);
> +	struct msm_dp *dp_display = dp_bridge->dp_display;
> +
> +	dp_display->internal_hpd = false;
> +}
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
> index dcedf021f7fe..371337d0fae2 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -21,6 +21,7 @@ struct msm_dp {
>   	bool power_on;
>   	unsigned int connector_type;
>   	bool is_edp;
> +	bool internal_hpd;
>   
>   	hdmi_codec_plugged_cb plugged_cb;
>   
> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
> index 6db82f9b03af..9d03b6ee3c41 100644
> --- a/drivers/gpu/drm/msm/dp/dp_drm.c
> +++ b/drivers/gpu/drm/msm/dp/dp_drm.c
> @@ -102,6 +102,8 @@ static const struct drm_bridge_funcs dp_bridge_ops = {
>   	.get_modes    = dp_bridge_get_modes,
>   	.detect       = dp_bridge_detect,
>   	.atomic_check = dp_bridge_atomic_check,
> +	.hpd_enable   = dp_bridge_hpd_enable,
> +	.hpd_disable  = dp_bridge_hpd_disable,
>   };
>   
>   struct drm_bridge *dp_bridge_init(struct msm_dp *dp_display, struct drm_device *dev,
> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.h b/drivers/gpu/drm/msm/dp/dp_drm.h
> index 82035dbb0578..1f871b555006 100644
> --- a/drivers/gpu/drm/msm/dp/dp_drm.h
> +++ b/drivers/gpu/drm/msm/dp/dp_drm.h
> @@ -32,5 +32,7 @@ enum drm_mode_status dp_bridge_mode_valid(struct drm_bridge *bridge,
>   void dp_bridge_mode_set(struct drm_bridge *drm_bridge,
>   			const struct drm_display_mode *mode,
>   			const struct drm_display_mode *adjusted_mode);
> +void dp_bridge_hpd_enable(struct drm_bridge *bridge);
> +void dp_bridge_hpd_disable(struct drm_bridge *bridge);
>   
>   #endif /* _DP_DRM_H_ */