Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <0da9f04d-c12a-8e6c-5ae9-94c3aa0589b2@linaro.org>
Date:   Mon, 11 Jul 2022 17:21:07 +0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.10.0
Subject: Re: [PATCH v6 04/10] drm/msm/dp: Add basic PSR support for eDP
Content-Language: en-GB
To:     Vinod Polimera <quic_vpolimer@quicinc.com>,
        dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
        freedreno@lists.freedesktop.org, devicetree@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, robdclark@gmail.com,
        dianders@chromium.org, swboyd@chromium.org,
        quic_kalyant@quicinc.com, quic_khsieh@quicinc.com,
        quic_vproddut@quicinc.com, bjorn.andersson@linaro.org,
        quic_aravindh@quicinc.com, quic_abhinavk@quicinc.com,
        quic_sbillaka@quicinc.com
References: <1657544224-10680-1-git-send-email-quic_vpolimer@quicinc.com>
 <1657544224-10680-5-git-send-email-quic_vpolimer@quicinc.com>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <1657544224-10680-5-git-send-email-quic_vpolimer@quicinc.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 11/07/2022 15:56, Vinod Polimera wrote:
> Add support for basic panel self refresh (PSR) feature for eDP.
> Add a new interface to set PSR state in the sink from DPU.
> Program the eDP controller to issue PSR enter and exit SDP to
> the sink.
> 
> Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com>
> Signed-off-by: Vinod Polimera <quic_vpolimer@quicinc.com>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

> ---
>   drivers/gpu/drm/msm/dp/dp_catalog.c |  81 ++++++++++++++++++++++
>   drivers/gpu/drm/msm/dp/dp_catalog.h |   4 ++
>   drivers/gpu/drm/msm/dp/dp_ctrl.c    |  73 +++++++++++++++++++
>   drivers/gpu/drm/msm/dp/dp_ctrl.h    |   3 +
>   drivers/gpu/drm/msm/dp/dp_display.c |  14 ++++
>   drivers/gpu/drm/msm/dp/dp_display.h |   2 +
>   drivers/gpu/drm/msm/dp/dp_drm.c     | 135 +++++++++++++++++++++++++++++++++++-
>   drivers/gpu/drm/msm/dp/dp_link.c    |  36 ++++++++++
>   drivers/gpu/drm/msm/dp/dp_panel.c   |  22 ++++++
>   drivers/gpu/drm/msm/dp/dp_panel.h   |   6 ++
>   drivers/gpu/drm/msm/dp/dp_reg.h     |  27 ++++++++
>   11 files changed, 402 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
> index 7257515..b9021ed 100644
> --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
> @@ -47,6 +47,14 @@
>   #define DP_INTERRUPT_STATUS2_MASK \
>   	(DP_INTERRUPT_STATUS2 << DP_INTERRUPT_STATUS_MASK_SHIFT)
>   
> +#define DP_INTERRUPT_STATUS4 \
> +	(PSR_UPDATE_INT | PSR_CAPTURE_INT | PSR_EXIT_INT | \
> +	PSR_UPDATE_ERROR_INT | PSR_WAKE_ERROR_INT)
> +
> +#define DP_INTERRUPT_MASK4 \
> +	(PSR_UPDATE_MASK | PSR_CAPTURE_MASK | PSR_EXIT_MASK | \
> +	PSR_UPDATE_ERROR_MASK | PSR_WAKE_ERROR_MASK)
> +
>   struct dp_catalog_private {
>   	struct device *dev;
>   	struct drm_device *drm_dev;
> @@ -359,6 +367,24 @@ void dp_catalog_ctrl_lane_mapping(struct dp_catalog *dp_catalog)
>   			ln_mapping);
>   }
>   
> +void dp_catalog_ctrl_psr_mainlink_enable(struct dp_catalog *dp_catalog,
> +						bool enable)
> +{
> +	u32 val;
> +	struct dp_catalog_private *catalog = container_of(dp_catalog,
> +				struct dp_catalog_private, dp_catalog);
> +
> +	val = dp_read_link(catalog, REG_DP_MAINLINK_CTRL);
> +	val &= ~DP_MAINLINK_CTRL_ENABLE;
> +
> +	if (enable)
> +		val |= DP_MAINLINK_CTRL_ENABLE;
> +	else
> +		val &= ~DP_MAINLINK_CTRL_ENABLE;
> +
> +	dp_write_link(catalog, REG_DP_MAINLINK_CTRL, val);
> +}
> +
>   void dp_catalog_ctrl_mainlink_ctrl(struct dp_catalog *dp_catalog,
>   						bool enable)
>   {
> @@ -610,6 +636,47 @@ void dp_catalog_ctrl_hpd_config(struct dp_catalog *dp_catalog)
>   	dp_write_aux(catalog, REG_DP_DP_HPD_CTRL, DP_DP_HPD_CTRL_HPD_EN);
>   }
>   
> +static void dp_catalog_enable_sdp(struct dp_catalog_private *catalog)
> +{
> +	/* trigger sdp */
> +	dp_write_link(catalog, MMSS_DP_SDP_CFG3, UPDATE_SDP);
> +	dp_write_link(catalog, MMSS_DP_SDP_CFG3, !UPDATE_SDP);
> +}
> +
> +void dp_catalog_ctrl_config_psr(struct dp_catalog *dp_catalog)
> +{
> +	struct dp_catalog_private *catalog = container_of(dp_catalog,
> +				struct dp_catalog_private, dp_catalog);
> +	u32 config;
> +
> +	/* enable PSR1 function */
> +	config = dp_read_link(catalog, REG_PSR_CONFIG);
> +	config |= PSR1_SUPPORTED;
> +	dp_write_link(catalog, REG_PSR_CONFIG, config);
> +
> +	dp_write_ahb(catalog, REG_DP_INTR_MASK4, DP_INTERRUPT_MASK4);
> +	dp_catalog_enable_sdp(catalog);
> +}
> +
> +void dp_catalog_ctrl_set_psr(struct dp_catalog *dp_catalog, bool enter)
> +{
> +	struct dp_catalog_private *catalog = container_of(dp_catalog,
> +			struct dp_catalog_private, dp_catalog);
> +	u32 cmd;
> +
> +	cmd = dp_read_link(catalog, REG_PSR_CMD);
> +
> +	cmd &= ~(PSR_ENTER | PSR_EXIT);
> +
> +	if (enter)
> +		cmd |= PSR_ENTER;
> +	else
> +		cmd |= PSR_EXIT;
> +
> +	dp_catalog_enable_sdp(catalog);
> +	dp_write_link(catalog, REG_PSR_CMD, cmd);
> +}
> +
>   u32 dp_catalog_link_is_connected(struct dp_catalog *dp_catalog)
>   {
>   	struct dp_catalog_private *catalog = container_of(dp_catalog,
> @@ -645,6 +712,20 @@ u32 dp_catalog_hpd_get_intr_status(struct dp_catalog *dp_catalog)
>   	return isr & (mask | ~DP_DP_HPD_INT_MASK);
>   }
>   
> +int dp_catalog_ctrl_read_psr_interrupt_status(struct dp_catalog *dp_catalog)
> +{
> +	struct dp_catalog_private *catalog = container_of(dp_catalog,
> +				struct dp_catalog_private, dp_catalog);
> +	u32 intr, intr_ack;
> +
> +	intr = dp_read_ahb(catalog, REG_DP_INTR_STATUS4);
> +	intr_ack = (intr & DP_INTERRUPT_STATUS4)
> +			<< DP_INTERRUPT_STATUS_ACK_SHIFT;
> +	dp_write_ahb(catalog, REG_DP_INTR_STATUS4, intr_ack);
> +
> +	return intr;
> +}
> +
>   int dp_catalog_ctrl_get_interrupt(struct dp_catalog *dp_catalog)
>   {
>   	struct dp_catalog_private *catalog = container_of(dp_catalog,
> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h
> index 1f717f4..6454845 100644
> --- a/drivers/gpu/drm/msm/dp/dp_catalog.h
> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
> @@ -93,6 +93,7 @@ void dp_catalog_ctrl_state_ctrl(struct dp_catalog *dp_catalog, u32 state);
>   void dp_catalog_ctrl_config_ctrl(struct dp_catalog *dp_catalog, u32 config);
>   void dp_catalog_ctrl_lane_mapping(struct dp_catalog *dp_catalog);
>   void dp_catalog_ctrl_mainlink_ctrl(struct dp_catalog *dp_catalog, bool enable);
> +void dp_catalog_ctrl_psr_mainlink_enable(struct dp_catalog *dp_catalog, bool enable);
>   void dp_catalog_ctrl_config_misc(struct dp_catalog *dp_catalog, u32 cc, u32 tb);
>   void dp_catalog_ctrl_config_msa(struct dp_catalog *dp_catalog, u32 rate,
>   				u32 stream_rate_khz, bool fixed_nvid);
> @@ -104,12 +105,15 @@ void dp_catalog_ctrl_enable_irq(struct dp_catalog *dp_catalog, bool enable);
>   void dp_catalog_hpd_config_intr(struct dp_catalog *dp_catalog,
>   			u32 intr_mask, bool en);
>   void dp_catalog_ctrl_hpd_config(struct dp_catalog *dp_catalog);
> +void dp_catalog_ctrl_config_psr(struct dp_catalog *dp_catalog);
> +void dp_catalog_ctrl_set_psr(struct dp_catalog *dp_catalog, bool enter);
>   u32 dp_catalog_link_is_connected(struct dp_catalog *dp_catalog);
>   u32 dp_catalog_hpd_get_intr_status(struct dp_catalog *dp_catalog);
>   void dp_catalog_ctrl_phy_reset(struct dp_catalog *dp_catalog);
>   int dp_catalog_ctrl_update_vx_px(struct dp_catalog *dp_catalog, u8 v_level,
>   				u8 p_level);
>   int dp_catalog_ctrl_get_interrupt(struct dp_catalog *dp_catalog);
> +int dp_catalog_ctrl_read_psr_interrupt_status(struct dp_catalog *dp_catalog);
>   void dp_catalog_ctrl_update_transfer_unit(struct dp_catalog *dp_catalog,
>   				u32 dp_tu, u32 valid_boundary,
>   				u32 valid_boundary2);
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index d21971b..0007920 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -22,6 +22,7 @@
>   
>   #define DP_KHZ_TO_HZ 1000
>   #define IDLE_PATTERN_COMPLETION_TIMEOUT_JIFFIES	(30 * HZ / 1000) /* 30 ms */
> +#define PSR_OPERATION_COMPLETION_TIMEOUT_JIFFIES       (300 * HZ / 1000) /* 300 ms */
>   #define WAIT_FOR_VIDEO_READY_TIMEOUT_JIFFIES (HZ / 2)
>   
>   #define DP_CTRL_INTR_READY_FOR_VIDEO     BIT(0)
> @@ -80,6 +81,7 @@ struct dp_ctrl_private {
>   	struct dp_catalog *catalog;
>   
>   	struct completion idle_comp;
> +	struct completion psr_op_comp;
>   	struct completion video_comp;
>   };
>   
> @@ -153,6 +155,9 @@ static void dp_ctrl_config_ctrl(struct dp_ctrl_private *ctrl)
>   	config |= DP_CONFIGURATION_CTRL_STATIC_DYNAMIC_CN;
>   	config |= DP_CONFIGURATION_CTRL_SYNC_ASYNC_CLK;
>   
> +	if (ctrl->panel->psr_cap.version)
> +		config |= DP_CONFIGURATION_CTRL_SEND_VSC;
> +
>   	dp_catalog_ctrl_config_ctrl(ctrl->catalog, config);
>   }
>   
> @@ -1394,6 +1399,60 @@ void dp_ctrl_reset_irq_ctrl(struct dp_ctrl *dp_ctrl, bool enable)
>   		dp_catalog_ctrl_enable_irq(ctrl->catalog, enable);
>   }
>   
> +void dp_ctrl_config_psr(struct dp_ctrl *dp_ctrl)
> +{
> +	u8 cfg;
> +	struct dp_ctrl_private *ctrl = container_of(dp_ctrl,
> +			struct dp_ctrl_private, dp_ctrl);
> +
> +	if (!ctrl->panel->psr_cap.version)
> +		return;
> +
> +	dp_catalog_ctrl_config_psr(ctrl->catalog);
> +
> +	cfg = DP_PSR_ENABLE;
> +	drm_dp_dpcd_write(ctrl->aux, DP_PSR_EN_CFG, &cfg, 1);
> +}
> +
> +void dp_ctrl_set_psr(struct dp_ctrl *dp_ctrl, bool enter)
> +{
> +	struct dp_ctrl_private *ctrl = container_of(dp_ctrl,
> +			struct dp_ctrl_private, dp_ctrl);
> +
> +	if (!ctrl->panel->psr_cap.version)
> +		return;
> +
> +	/*
> +	 * When entering PSR,
> +	 * 1. Send PSR enter SDP and wait for the PSR_UPDATE_INT
> +	 * 2. Turn off video
> +	 * 3. Disable the mainlink
> +	 *
> +	 * When exiting PSR,
> +	 * 1. Enable the mainlink
> +	 * 2. Send the PSR exit SDP
> +	 */
> +	if (enter) {
> +		reinit_completion(&ctrl->psr_op_comp);
> +		dp_catalog_ctrl_set_psr(ctrl->catalog, true);
> +
> +		if (!wait_for_completion_timeout(&ctrl->psr_op_comp,
> +			PSR_OPERATION_COMPLETION_TIMEOUT_JIFFIES)) {
> +			DRM_ERROR("PSR_ENTRY timedout\n");
> +			dp_catalog_ctrl_set_psr(ctrl->catalog, false);
> +			return;
> +		}
> +
> +		dp_catalog_ctrl_state_ctrl(ctrl->catalog, 0);
> +
> +		dp_catalog_ctrl_psr_mainlink_enable(ctrl->catalog, false);
> +	} else {
> +		dp_catalog_ctrl_psr_mainlink_enable(ctrl->catalog, true);
> +
> +		dp_catalog_ctrl_set_psr(ctrl->catalog, false);
> +	}
> +}
> +
>   void dp_ctrl_phy_init(struct dp_ctrl *dp_ctrl)
>   {
>   	struct dp_ctrl_private *ctrl;
> @@ -1997,6 +2056,19 @@ void dp_ctrl_isr(struct dp_ctrl *dp_ctrl)
>   
>   	ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl);
>   
> +	if (ctrl->panel->psr_cap.version) {
> +		isr = dp_catalog_ctrl_read_psr_interrupt_status(ctrl->catalog);
> +
> +		if (isr)
> +			complete(&ctrl->psr_op_comp);
> +
> +		if (isr & PSR_EXIT_INT)
> +			drm_dbg_dp(ctrl->drm_dev, "PSR exit done\n");
> +
> +		if (isr & PSR_UPDATE_INT)
> +			drm_dbg_dp(ctrl->drm_dev, "PSR frame update done\n");
> +	}
> +
>   	isr = dp_catalog_ctrl_get_interrupt(ctrl->catalog);
>   
>   	if (isr & DP_CTRL_INTR_READY_FOR_VIDEO) {
> @@ -2043,6 +2115,7 @@ struct dp_ctrl *dp_ctrl_get(struct device *dev, struct dp_link *link,
>   		dev_err(dev, "failed to add DP OPP table\n");
>   
>   	init_completion(&ctrl->idle_comp);
> +	init_completion(&ctrl->psr_op_comp);
>   	init_completion(&ctrl->video_comp);
>   
>   	/* in parameters */
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.h b/drivers/gpu/drm/msm/dp/dp_ctrl.h
> index 0745fde..be074ae 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.h
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.h
> @@ -38,4 +38,7 @@ void dp_ctrl_phy_init(struct dp_ctrl *dp_ctrl);
>   void dp_ctrl_phy_exit(struct dp_ctrl *dp_ctrl);
>   void dp_ctrl_irq_phy_exit(struct dp_ctrl *dp_ctrl);
>   
> +void dp_ctrl_set_psr(struct dp_ctrl *dp_ctrl, bool enable);
> +void dp_ctrl_config_psr(struct dp_ctrl *dp_ctrl);
> +
>   #endif /* _DP_CTRL_H_ */
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 5bd6677..64a6254 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -388,6 +388,8 @@ static int dp_display_process_hpd_high(struct dp_display_private *dp)
>   
>   	edid = dp->panel->edid;
>   
> +	dp->dp_display.psr_supported = !!dp->panel->psr_cap.version;
> +
>   	dp->audio_supported = drm_detect_monitor_audio(edid);
>   	dp_panel_handle_sink_request(dp->panel);
>   
> @@ -895,6 +897,10 @@ static int dp_display_post_enable(struct msm_dp *dp_display)
>   
>   	/* signal the connect event late to synchronize video and display */
>   	dp_display_handle_plugged_change(dp_display, true);
> +
> +	if (dp_display->psr_supported)
> +		dp_ctrl_config_psr(dp->ctrl);
> +
>   	return 0;
>   }
>   
> @@ -1094,6 +1100,14 @@ static void dp_display_config_hpd(struct dp_display_private *dp)
>   	enable_irq(dp->irq);
>   }
>   
> +void dp_display_set_psr(struct msm_dp *dp_display, bool enter)
> +{
> +	struct dp_display_private *dp;
> +
> +	dp = container_of(dp_display, struct dp_display_private, dp_display);
> +	dp_ctrl_set_psr(dp->ctrl, enter);
> +}
> +
>   static int hpd_event_thread(void *data)
>   {
>   	struct dp_display_private *dp_priv;
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
> index 4f9fe4d..1feaada 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.h
> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
> @@ -29,6 +29,7 @@ struct msm_dp {
>   
>   	u32 max_dp_lanes;
>   	struct dp_audio *dp_audio;
> +	bool psr_supported;
>   };
>   
>   int dp_display_set_plugged_cb(struct msm_dp *dp_display,
> @@ -39,5 +40,6 @@ bool dp_display_check_video_test(struct msm_dp *dp_display);
>   int dp_display_get_test_bpp(struct msm_dp *dp_display);
>   void dp_display_signal_audio_start(struct msm_dp *dp_display);
>   void dp_display_signal_audio_complete(struct msm_dp *dp_display);
> +void dp_display_set_psr(struct msm_dp *dp, bool enter);
>   
>   #endif /* _DP_DISPLAY_H_ */
> diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
> index 294c28a..8ca0b37 100644
> --- a/drivers/gpu/drm/msm/dp/dp_drm.c
> +++ b/drivers/gpu/drm/msm/dp/dp_drm.c
> @@ -60,6 +60,139 @@ static int dp_bridge_get_modes(struct drm_bridge *bridge, struct drm_connector *
>   	return rc;
>   }
>   
> +static int edp_bridge_atomic_check(struct drm_bridge *drm_bridge,
> +				   struct drm_bridge_state *bridge_state,
> +				   struct drm_crtc_state *crtc_state,
> +				   struct drm_connector_state *conn_state)
> +{
> +	struct msm_dp *dp = to_dp_bridge(drm_bridge)->dp_display;
> +
> +	if (WARN_ON(!conn_state))
> +		return -ENODEV;
> +
> +	conn_state->self_refresh_aware = dp->psr_supported;
> +
> +	if (!conn_state->crtc || !crtc_state)
> +		return 0;
> +
> +	if (crtc_state->self_refresh_active && !dp->psr_supported)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static void edp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
> +				     struct drm_bridge_state *old_bridge_state)
> +{
> +	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
> +	struct drm_crtc *crtc;
> +	struct drm_crtc_state *old_crtc_state;
> +	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
> +	struct msm_dp *dp = dp_bridge->dp_display;
> +
> +	/*
> +	 * Check the old state of the crtc to determine if the panel
> +	 * was put into psr state previously by the edp_bridge_atomic_disable.
> +	 * If the panel is in psr, just exit psr state and skip the full
> +	 * bridge enable sequence.
> +	 */
> +	crtc = drm_atomic_get_new_crtc_for_encoder(atomic_state,
> +						   drm_bridge->encoder);
> +	if (!crtc)
> +		return;
> +
> +	old_crtc_state = drm_atomic_get_old_crtc_state(atomic_state, crtc);
> +
> +	if (old_crtc_state && old_crtc_state->self_refresh_active) {
> +		dp_display_set_psr(dp, false);
> +		return;
> +	}
> +
> +	dp_bridge_atomic_enable(drm_bridge, old_bridge_state);
> +}
> +
> +static void edp_bridge_atomic_disable(struct drm_bridge *drm_bridge,
> +				      struct drm_bridge_state *old_bridge_state)
> +{
> +	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
> +	struct drm_crtc *crtc;
> +	struct drm_crtc_state *new_crtc_state = NULL, *old_crtc_state = NULL;
> +	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
> +	struct msm_dp *dp = dp_bridge->dp_display;
> +
> +	crtc = drm_atomic_get_old_crtc_for_encoder(atomic_state,
> +						   drm_bridge->encoder);
> +	if (!crtc)
> +		goto out;
> +
> +	new_crtc_state = drm_atomic_get_new_crtc_state(atomic_state, crtc);
> +	if (!new_crtc_state)
> +		goto out;
> +
> +	old_crtc_state = drm_atomic_get_old_crtc_state(atomic_state, crtc);
> +	if (!old_crtc_state)
> +		goto out;
> +
> +	/*
> +	 * Set self refresh mode if current crtc state is active.
> +	 *
> +	 * If old crtc state is active, then this is a display disable
> +	 * call while the sink is in psr state. So, exit psr here.
> +	 * The eDP controller will be disabled in the
> +	 * edp_bridge_atomic_post_disable function.
> +	 *
> +	 * We observed sink is stuck in self refresh if psr exit is skipped
> +	 * when display disable occurs while the sink is in psr state.
> +	 */
> +	if (new_crtc_state->self_refresh_active) {
> +		dp_display_set_psr(dp, true);
> +		return;
> +	} else if (old_crtc_state->self_refresh_active) {
> +		dp_display_set_psr(dp, false);
> +		return;
> +	}
> +
> +out:
> +	dp_bridge_atomic_disable(drm_bridge, old_bridge_state);
> +}
> +
> +static void edp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
> +				struct drm_bridge_state *old_bridge_state)
> +{
> +	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
> +	struct drm_crtc *crtc;
> +	struct drm_crtc_state *new_crtc_state = NULL;
> +
> +	crtc = drm_atomic_get_old_crtc_for_encoder(atomic_state,
> +						   drm_bridge->encoder);
> +	if (!crtc)
> +		return;
> +
> +	new_crtc_state = drm_atomic_get_new_crtc_state(atomic_state, crtc);
> +	if (!new_crtc_state)
> +		return;
> +
> +	/*
> +	 * Self refresh mode is already set in edp_bridge_atomic_disable.
> +	 */
> +	if (new_crtc_state->self_refresh_active)
> +		return;
> +
> +	dp_bridge_atomic_post_disable(drm_bridge, old_bridge_state);
> +}
> +
> +static const struct drm_bridge_funcs edp_bridge_ops = {
> +	.atomic_enable = edp_bridge_atomic_enable,
> +	.atomic_disable = edp_bridge_atomic_disable,
> +	.atomic_post_disable = edp_bridge_atomic_post_disable,
> +	.mode_set = dp_bridge_mode_set,
> +	.mode_valid = dp_bridge_mode_valid,
> +	.atomic_reset = drm_atomic_helper_bridge_reset,
> +	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> +	.atomic_check = edp_bridge_atomic_check,
> +};
> +
>   static const struct drm_bridge_funcs dp_bridge_ops = {
>   	.atomic_enable = dp_bridge_atomic_enable,
>   	.atomic_disable = dp_bridge_atomic_disable,
> @@ -87,7 +220,7 @@ struct drm_bridge *dp_bridge_init(struct msm_dp *dp_display, struct drm_device *
>   	dp_bridge->dp_display = dp_display;
>   
>   	bridge = &dp_bridge->bridge;
> -	bridge->funcs = &dp_bridge_ops;
> +	bridge->funcs = dp_display->is_edp ? &edp_bridge_ops : &dp_bridge_ops;
>   	bridge->type = dp_display->connector_type;
>   
>   	/*
> diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
> index 36f0af0..84af70a 100644
> --- a/drivers/gpu/drm/msm/dp/dp_link.c
> +++ b/drivers/gpu/drm/msm/dp/dp_link.c
> @@ -934,6 +934,38 @@ static int dp_link_process_phy_test_pattern_request(
>   	return 0;
>   }
>   
> +static bool dp_link_read_psr_error_status(struct dp_link_private *link)
> +{
> +	u8 status;
> +
> +	drm_dp_dpcd_read(link->aux, DP_PSR_ERROR_STATUS, &status, 1);
> +
> +	if (status & DP_PSR_LINK_CRC_ERROR)
> +		DRM_ERROR("PSR LINK CRC ERROR\n");
> +	else if (status & DP_PSR_RFB_STORAGE_ERROR)
> +		DRM_ERROR("PSR RFB STORAGE ERROR\n");
> +	else if (status & DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR)
> +		DRM_ERROR("PSR VSC SDP UNCORRECTABLE ERROR\n");
> +	else
> +		return false;
> +
> +	return true;
> +}
> +
> +static bool dp_link_psr_capability_changed(struct dp_link_private *link)
> +{
> +	u8 status;
> +
> +	drm_dp_dpcd_read(link->aux, DP_PSR_ESI, &status, 1);
> +
> +	if (status & DP_PSR_CAPS_CHANGE) {
> +		drm_dbg_dp(link->drm_dev, "PSR Capability Change\n");
> +		return true;
> +	}
> +
> +	return false;
> +}
> +
>   static u8 get_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
>   {
>   	return link_status[r - DP_LANE0_1_STATUS];
> @@ -1053,6 +1085,10 @@ int dp_link_process_request(struct dp_link *dp_link)
>   		dp_link->sink_request |= DP_TEST_LINK_TRAINING;
>   	} else if (!dp_link_process_phy_test_pattern_request(link)) {
>   		dp_link->sink_request |= DP_TEST_LINK_PHY_TEST_PATTERN;
> +	} else if (dp_link_read_psr_error_status(link)) {
> +		DRM_ERROR("PSR IRQ_HPD received\n");
> +	} else if (dp_link_psr_capability_changed(link)) {
> +		drm_dbg_dp(link->drm_dev, "PSR Capabiity changed");
>   	} else {
>   		ret = dp_link_process_link_status_update(link);
>   		if (!ret) {
> diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
> index 5149ceb..8bf8ab4 100644
> --- a/drivers/gpu/drm/msm/dp/dp_panel.c
> +++ b/drivers/gpu/drm/msm/dp/dp_panel.c
> @@ -20,6 +20,27 @@ struct dp_panel_private {
>   	bool aux_cfg_update_done;
>   };
>   
> +static void dp_panel_read_psr_cap(struct dp_panel_private *panel)
> +{
> +	ssize_t rlen;
> +	struct dp_panel *dp_panel;
> +
> +	dp_panel = &panel->dp_panel;
> +
> +	/* edp sink */
> +	if (dp_panel->dpcd[DP_EDP_CONFIGURATION_CAP]) {
> +		rlen = drm_dp_dpcd_read(panel->aux, DP_PSR_SUPPORT,
> +				&dp_panel->psr_cap, sizeof(dp_panel->psr_cap));
> +		if (rlen == sizeof(dp_panel->psr_cap)) {
> +			drm_dbg_dp(panel->drm_dev,
> +				"psr version: 0x%x, psr_cap: 0x%x\n",
> +				dp_panel->psr_cap.version,
> +				dp_panel->psr_cap.capabilities);
> +		} else
> +			DRM_ERROR("failed to read psr info, rlen=%zd\n", rlen);
> +	}
> +}
> +
>   static int dp_panel_read_dpcd(struct dp_panel *dp_panel)
>   {
>   	int rc = 0;
> @@ -106,6 +127,7 @@ static int dp_panel_read_dpcd(struct dp_panel *dp_panel)
>   		}
>   	}
>   
> +	dp_panel_read_psr_cap(panel);
>   end:
>   	return rc;
>   }
> diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h
> index d861197a..2d0826a 100644
> --- a/drivers/gpu/drm/msm/dp/dp_panel.h
> +++ b/drivers/gpu/drm/msm/dp/dp_panel.h
> @@ -34,6 +34,11 @@ struct dp_panel_in {
>   	struct dp_catalog *catalog;
>   };
>   
> +struct dp_panel_psr {
> +	u8 version;
> +	u8 capabilities;
> +};
> +
>   struct dp_panel {
>   	/* dpcd raw data */
>   	u8 dpcd[DP_RECEIVER_CAP_SIZE + 1];
> @@ -46,6 +51,7 @@ struct dp_panel {
>   	struct edid *edid;
>   	struct drm_connector *connector;
>   	struct dp_display_mode dp_mode;
> +	struct dp_panel_psr psr_cap;
>   	bool video_test;
>   
>   	u32 vic;
> diff --git a/drivers/gpu/drm/msm/dp/dp_reg.h b/drivers/gpu/drm/msm/dp/dp_reg.h
> index 2686028..ea85a69 100644
> --- a/drivers/gpu/drm/msm/dp/dp_reg.h
> +++ b/drivers/gpu/drm/msm/dp/dp_reg.h
> @@ -22,6 +22,20 @@
>   #define REG_DP_INTR_STATUS2			(0x00000024)
>   #define REG_DP_INTR_STATUS3			(0x00000028)
>   
> +#define REG_DP_INTR_STATUS4			(0x0000002C)
> +#define PSR_UPDATE_INT				(0x00000001)
> +#define PSR_CAPTURE_INT				(0x00000004)
> +#define PSR_EXIT_INT				(0x00000010)
> +#define PSR_UPDATE_ERROR_INT			(0x00000040)
> +#define PSR_WAKE_ERROR_INT			(0x00000100)
> +
> +#define REG_DP_INTR_MASK4			(0x00000030)
> +#define PSR_UPDATE_MASK				(0x00000001)
> +#define PSR_CAPTURE_MASK			(0x00000002)
> +#define PSR_EXIT_MASK				(0x00000004)
> +#define PSR_UPDATE_ERROR_MASK			(0x00000008)
> +#define PSR_WAKE_ERROR_MASK			(0x00000010)
> +
>   #define REG_DP_DP_HPD_CTRL			(0x00000000)
>   #define DP_DP_HPD_CTRL_HPD_EN			(0x00000001)
>   
> @@ -164,6 +178,16 @@
>   #define MMSS_DP_AUDIO_TIMING_RBR_48		(0x00000094)
>   #define MMSS_DP_AUDIO_TIMING_HBR_48		(0x00000098)
>   
> +#define REG_PSR_CONFIG				(0x00000100)
> +#define DISABLE_PSR				(0x00000000)
> +#define PSR1_SUPPORTED				(0x00000001)
> +#define PSR2_WITHOUT_FRAMESYNC			(0x00000002)
> +#define PSR2_WITH_FRAMESYNC			(0x00000003)
> +
> +#define REG_PSR_CMD				(0x00000110)
> +#define PSR_ENTER				(0x00000001)
> +#define PSR_EXIT				(0x00000002)
> +
>   #define MMSS_DP_PSR_CRC_RG			(0x00000154)
>   #define MMSS_DP_PSR_CRC_B			(0x00000158)
>   
> @@ -184,6 +208,9 @@
>   #define MMSS_DP_AUDIO_STREAM_0			(0x00000240)
>   #define MMSS_DP_AUDIO_STREAM_1			(0x00000244)
>   
> +#define MMSS_DP_SDP_CFG3			(0x0000024c)
> +#define UPDATE_SDP				(0x00000001)
> +
>   #define MMSS_DP_EXTENSION_0			(0x00000250)
>   #define MMSS_DP_EXTENSION_1			(0x00000254)
>   #define MMSS_DP_EXTENSION_2			(0x00000258)


-- 
With best wishes
Dmitry