Re: [PATCH v3] drm/msm/dp: do not initialize phy until plugin interrupt received

[Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>]

On 11/8/2021 4:29 PM, Bjorn Andersson wrote:
> On Mon 08 Nov 15:42 PST 2021, Kuogee Hsieh wrote:
>
> > From: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
> >
> > Combo phy supports both USB and DP simultaneously. There may has a
> > possible conflict during phy initialization phase between USB and
> > DP driver which may cause USB phy timeout when USB tries to power
> > up its phy. This patch has the DP driver not initialize its phy
> > during DP driver initialization phase. Instead DP driver only enable
> > required regulators and clocks so that it is able to receive HPD
> > interrupts after completion of initialization phase. DP driver will
> > initialize its phy when HPD plug-in interrupt received.
> > This patch also provides a positive side effects which balance regulator
> > enable count since regulator only enabled at initialize phase and resume
> > and disabled at followed suspend.
> I thought you said that you (someone) will attempt to resolve the
> described error in the QMP driver, making this patch unnecessary.
>
> That said, are there any other benefits to this patch? I.e. does it make
> sense not to initialize the phy when there's no cable connected for
> power purposed etc?
> If so this patch looks reasonable in itself, but the commit message is
> wrong.
>
> Thanks,
> Bjorn

sorry for the confusing.

I will redo the commit test.

Thanks,

> > Changes in V2:
> > -- removed unnecessary dp_ctrl NULL check
> > -- removed unnecessary phy init_count and power_count DRM_DEBUG_DP logs
> > -- remove flip parameter out of dp_ctrl_irq_enable()
> > -- add fixes tag
> >
> > Changes in V3:
> > -- call dp_display_host_phy_init() instead of dp_ctrl_phy_init() at dp_display_host_init() for eDP
> >
> > Fixes: e91e3065a806 ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets")
> >
> > Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/msm/dp/dp_ctrl.c    | 87 ++++++++++++++++---------------------
> >   drivers/gpu/drm/msm/dp/dp_ctrl.h    |  9 ++--
> >   drivers/gpu/drm/msm/dp/dp_display.c | 83 ++++++++++++++++++++++++++---------
> >   3 files changed, 105 insertions(+), 74 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > index 7ec155d..4788e8c 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> > @@ -1364,60 +1364,54 @@ static int dp_ctrl_enable_stream_clocks(struct dp_ctrl_private *ctrl)
> >   	return ret;
> >   }
> >   
> > -int dp_ctrl_host_init(struct dp_ctrl *dp_ctrl, bool flip, bool reset)
> > +void dp_ctrl_irq_enable(struct dp_ctrl *dp_ctrl)
> > +{
> > +	struct dp_ctrl_private *ctrl;
> > +
> > +	ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl);
> > +
> > +	dp_catalog_ctrl_reset(ctrl->catalog);
> > +
> > +	dp_catalog_ctrl_enable_irq(ctrl->catalog, true);
> > +}
> > +
> > +void dp_ctrl_irq_disable(struct dp_ctrl *dp_ctrl)
> > +{
> > +	struct dp_ctrl_private *ctrl;
> > +
> > +	ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl);
> > +
> > +	dp_catalog_ctrl_reset(ctrl->catalog);
> > +
> > +	dp_catalog_ctrl_enable_irq(ctrl->catalog, false);
> > +}
> > +
> > +void dp_ctrl_phy_init(struct dp_ctrl *dp_ctrl)
> >   {
> >   	struct dp_ctrl_private *ctrl;
> >   	struct dp_io *dp_io;
> >   	struct phy *phy;
> >   
> > -	if (!dp_ctrl) {
> > -		DRM_ERROR("Invalid input data\n");
> > -		return -EINVAL;
> > -	}
> > -
> >   	ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl);
> >   	dp_io = &ctrl->parser->io;
> >   	phy = dp_io->phy;
> >   
> > -	ctrl->dp_ctrl.orientation = flip;
> > -
> > -	if (reset)
> > -		dp_catalog_ctrl_reset(ctrl->catalog);
> > -
> > -	DRM_DEBUG_DP("flip=%d\n", flip);
> >   	dp_catalog_ctrl_phy_reset(ctrl->catalog);
> >   	phy_init(phy);
> > -	dp_catalog_ctrl_enable_irq(ctrl->catalog, true);
> > -
> > -	return 0;
> >   }
> >   
> > -/**
> > - * dp_ctrl_host_deinit() - Uninitialize DP controller
> > - * @dp_ctrl: Display Port Driver data
> > - *
> > - * Perform required steps to uninitialize DP controller
> > - * and its resources.
> > - */
> > -void dp_ctrl_host_deinit(struct dp_ctrl *dp_ctrl)
> > +void dp_ctrl_phy_exit(struct dp_ctrl *dp_ctrl)
> >   {
> >   	struct dp_ctrl_private *ctrl;
> >   	struct dp_io *dp_io;
> >   	struct phy *phy;
> >   
> > -	if (!dp_ctrl) {
> > -		DRM_ERROR("Invalid input data\n");
> > -		return;
> > -	}
> > -
> >   	ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl);
> >   	dp_io = &ctrl->parser->io;
> >   	phy = dp_io->phy;
> >   
> > -	dp_catalog_ctrl_enable_irq(ctrl->catalog, false);
> > +	dp_catalog_ctrl_phy_reset(ctrl->catalog);
> >   	phy_exit(phy);
> > -
> > -	DRM_DEBUG_DP("Host deinitialized successfully\n");
> >   }
> >   
> >   static bool dp_ctrl_use_fixed_nvid(struct dp_ctrl_private *ctrl)
> > @@ -1895,8 +1889,14 @@ int dp_ctrl_off_link_stream(struct dp_ctrl *dp_ctrl)
> >   		return ret;
> >   	}
> >   
> > +	DRM_DEBUG_DP("Before, phy=%x init_count=%d power_on=%d\n",
> > +		(u32)(uintptr_t)phy, phy->init_count, phy->power_count);
> > +
> >   	phy_power_off(phy);
> >   
> > +	DRM_DEBUG_DP("After, phy=%x init_count=%d power_on=%d\n",
> > +		(u32)(uintptr_t)phy, phy->init_count, phy->power_count);
> > +
> >   	/* aux channel down, reinit phy */
> >   	phy_exit(phy);
> >   	phy_init(phy);
> > @@ -1905,23 +1905,6 @@ int dp_ctrl_off_link_stream(struct dp_ctrl *dp_ctrl)
> >   	return ret;
> >   }
> >   
> > -void dp_ctrl_off_phy(struct dp_ctrl *dp_ctrl)
> > -{
> > -	struct dp_ctrl_private *ctrl;
> > -	struct dp_io *dp_io;
> > -	struct phy *phy;
> > -
> > -	ctrl = container_of(dp_ctrl, struct dp_ctrl_private, dp_ctrl);
> > -	dp_io = &ctrl->parser->io;
> > -	phy = dp_io->phy;
> > -
> > -	dp_catalog_ctrl_reset(ctrl->catalog);
> > -
> > -	phy_exit(phy);
> > -
> > -	DRM_DEBUG_DP("DP off phy done\n");
> > -}
> > -
> >   int dp_ctrl_off(struct dp_ctrl *dp_ctrl)
> >   {
> >   	struct dp_ctrl_private *ctrl;
> > @@ -1949,10 +1932,14 @@ int dp_ctrl_off(struct dp_ctrl *dp_ctrl)
> >   		DRM_ERROR("Failed to disable link clocks. ret=%d\n", ret);
> >   	}
> >   
> > +	DRM_DEBUG_DP("Before, phy=%x init_count=%d power_on=%d\n",
> > +		(u32)(uintptr_t)phy, phy->init_count, phy->power_count);
> > +
> >   	phy_power_off(phy);
> > -	phy_exit(phy);
> >   
> > -	DRM_DEBUG_DP("DP off done\n");
> > +	DRM_DEBUG_DP("After, phy=%x init_count=%d power_on=%d\n",
> > +		(u32)(uintptr_t)phy, phy->init_count, phy->power_count);
> > +
> >   	return ret;
> >   }
> >   
> > diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.h b/drivers/gpu/drm/msm/dp/dp_ctrl.h
> > index 2363a2d..30f9414 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_ctrl.h
> > +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.h
> > @@ -19,12 +19,9 @@ struct dp_ctrl {
> >   	u32 pixel_rate;
> >   };
> >   
> > -int dp_ctrl_host_init(struct dp_ctrl *dp_ctrl, bool flip, bool reset);
> > -void dp_ctrl_host_deinit(struct dp_ctrl *dp_ctrl);
> >   int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl);
> >   int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl);
> >   int dp_ctrl_off_link_stream(struct dp_ctrl *dp_ctrl);
> > -void dp_ctrl_off_phy(struct dp_ctrl *dp_ctrl);
> >   int dp_ctrl_off(struct dp_ctrl *dp_ctrl);
> >   void dp_ctrl_push_idle(struct dp_ctrl *dp_ctrl);
> >   void dp_ctrl_isr(struct dp_ctrl *dp_ctrl);
> > @@ -34,4 +31,10 @@ struct dp_ctrl *dp_ctrl_get(struct device *dev, struct dp_link *link,
> >   			struct dp_power *power, struct dp_catalog *catalog,
> >   			struct dp_parser *parser);
> >   
> > +void dp_ctrl_irq_enable(struct dp_ctrl *dp_ctrl);
> > +void dp_ctrl_irq_disable(struct dp_ctrl *dp_ctrl);
> > +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);
> > +
> >   #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 e41dd40..2f113ff 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > @@ -84,6 +84,7 @@ struct dp_display_private {
> >   
> >   	/* state variables */
> >   	bool core_initialized;
> > +	bool phy_initialized;
> >   	bool hpd_irq_on;
> >   	bool audio_supported;
> >   
> > @@ -387,7 +388,29 @@ static int dp_display_process_hpd_high(struct dp_display_private *dp)
> >   	return rc;
> >   }
> >   
> > -static void dp_display_host_init(struct dp_display_private *dp, int reset)
> > +static void dp_display_host_phy_init(struct dp_display_private *dp)
> > +{
> > +	DRM_DEBUG_DP("core_init=%d phy_init=%d\n",
> > +			dp->core_initialized, dp->phy_initialized);
> > +
> > +	if (!dp->phy_initialized) {
> > +		dp_ctrl_phy_init(dp->ctrl);
> > +		dp->phy_initialized = true;
> > +	}
> > +}
> > +
> > +static void dp_display_host_phy_exit(struct dp_display_private *dp)
> > +{
> > +	DRM_DEBUG_DP("core_init=%d phy_init=%d\n",
> > +			dp->core_initialized, dp->phy_initialized);
> > +
> > +	if (dp->phy_initialized) {
> > +		dp_ctrl_phy_exit(dp->ctrl);
> > +		dp->phy_initialized = false;
> > +	}
> > +}
> > +
> > +static void dp_display_host_init(struct dp_display_private *dp)
> >   {
> >   	bool flip = false;
> >   
> > @@ -400,8 +423,16 @@ static void dp_display_host_init(struct dp_display_private *dp, int reset)
> >   	if (dp->usbpd->orientation == ORIENTATION_CC2)
> >   		flip = true;
> >   
> > -	dp_power_init(dp->power, flip);
> > -	dp_ctrl_host_init(dp->ctrl, flip, reset);
> > +	dp_power_init(dp->power, false);
> > +	dp_ctrl_irq_enable(dp->ctrl);
> > +
> > +	/*
> > +	 * eDP is the embedded primary display and has its own phy
> > +	 * initialize phy immediately
> > +	 */
> > +	if (dp->dp_display.connector_type == DRM_MODE_CONNECTOR_eDP)
> > +		dp_display_host_phy_init(dp);
> > +
> >   	dp_aux_init(dp->aux);
> >   	dp->core_initialized = true;
> >   }
> > @@ -413,7 +444,7 @@ static void dp_display_host_deinit(struct dp_display_private *dp)
> >   		return;
> >   	}
> >   
> > -	dp_ctrl_host_deinit(dp->ctrl);
> > +	dp_ctrl_irq_disable(dp->ctrl);
> >   	dp_aux_deinit(dp->aux);
> >   	dp_power_deinit(dp->power);
> >   
> > @@ -424,7 +455,7 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
> >   {
> >   	struct dp_display_private *dp = dev_get_dp_display_private(dev);
> >   
> > -	dp_display_host_init(dp, true);
> > +	dp_display_host_phy_init(dp);
> >   
> >   	return dp_display_process_hpd_high(dp);
> >   }
> > @@ -551,7 +582,7 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
> >   		dp->hpd_state = ST_DISCONNECTED;
> >   
> >   		if (ret == -ECONNRESET) { /* cable unplugged */
> > -			dp->core_initialized = false;
> > +			dp->phy_initialized = false;
> >   		}
> >   
> >   	} else {
> > @@ -623,9 +654,8 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
> >   	if (state == ST_DISCONNECTED) {
> >   		/* triggered by irq_hdp with sink_count = 0 */
> >   		if (dp->link->sink_count == 0) {
> > -			dp_ctrl_off_phy(dp->ctrl);
> > +			dp_display_host_phy_exit(dp);
> >   			hpd->hpd_high = 0;
> > -			dp->core_initialized = false;
> >   		}
> >   		mutex_unlock(&dp->event_mutex);
> >   		return 0;
> > @@ -716,7 +746,7 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
> >   
> >   	ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
> >   	if (ret == -ECONNRESET) { /* cable unplugged */
> > -		dp->core_initialized = false;
> > +		dp->phy_initialized = false;
> >   	}
> >   	DRM_DEBUG_DP("hpd_state=%d\n", state);
> >   
> > @@ -918,12 +948,19 @@ static int dp_display_disable(struct dp_display_private *dp, u32 data)
> >   
> >   	dp_display->audio_enabled = false;
> >   
> > -	/* triggered by irq_hpd with sink_count = 0 */
> >   	if (dp->link->sink_count == 0) {
> > +		/*
> > +		 * irq_hpd with sink_count = 0
> > +		 * hdmi unplugged out of dongle
> > +		 */
> >   		dp_ctrl_off_link_stream(dp->ctrl);
> >   	} else {
> > +		/*
> > +		 * unplugged interrupt
> > +		 * dongle unplugged out of DUT
> > +		 */
> >   		dp_ctrl_off(dp->ctrl);
> > -		dp->core_initialized = false;
> > +		dp_display_host_phy_exit(dp);
> >   	}
> >   
> >   	dp_power_panel_on(dp->power, false);
> > @@ -1059,7 +1096,7 @@ void msm_dp_snapshot(struct msm_disp_state *disp_state, struct msm_dp *dp)
> >   static void dp_display_config_hpd(struct dp_display_private *dp)
> >   {
> >   
> > -	dp_display_host_init(dp, true);
> > +	dp_display_host_init(dp);
> >   	dp_catalog_ctrl_hpd_config(dp->catalog);
> >   
> >   	/* Enable interrupt first time
> > @@ -1338,20 +1375,22 @@ static int dp_pm_resume(struct device *dev)
> >   	dp->hpd_state = ST_DISCONNECTED;
> >   
> >   	/* turn on dp ctrl/phy */
> > -	dp_display_host_init(dp, true);
> > +	dp_display_host_init(dp);
> >   
> >   	dp_catalog_ctrl_hpd_config(dp->catalog);
> >   
> > -	/*
> > -	 * set sink to normal operation mode -- D0
> > -	 * before dpcd read
> > -	 */
> > -	dp_link_psm_config(dp->link, &dp->panel->link_info, false);
> > -
> >   	if (dp_catalog_link_is_connected(dp->catalog)) {
> > +		/*
> > +		 * set sink to normal operation mode -- D0
> > +		 * before dpcd read
> > +		 */
> > +		dp_display_host_phy_init(dp);
> > +		dp_link_psm_config(dp->link, &dp->panel->link_info, false);
> >   		sink_count = drm_dp_read_sink_count(dp->aux);
> >   		if (sink_count < 0)
> >   			sink_count = 0;
> > +
> > +		dp_display_host_phy_exit(dp);
> >   	}
> >   
> >   	dp->link->sink_count = sink_count;
> > @@ -1399,6 +1438,8 @@ static int dp_pm_suspend(struct device *dev)
> >   		dp_display_host_deinit(dp);
> >   	}
> >   
> > +	dp_display_host_phy_exit(dp);
> > +
> >   	dp->hpd_state = ST_SUSPENDED;
> >   
> >   	/* host_init will be called at pm_resume */
> > @@ -1473,7 +1514,7 @@ void msm_dp_irq_postinstall(struct msm_dp *dp_display)
> >   		enable_irq(dp->irq);
> >   		dp_hpd_connect(dp->usbpd, true);
> >   	} else {
> > -		dp_add_event(dp, EV_HPD_INIT_SETUP, 0, dp->id * 10);
> > +		dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 0);
> >   	}
> >   }
> >   
> > @@ -1567,7 +1608,7 @@ int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder)
> >   	state =  dp_display->hpd_state;
> >   
> >   	if (state == ST_DISPLAY_OFF)
> > -		dp_display_host_init(dp_display, true);
> > +		dp_display_host_phy_init(dp_display);
> >   
> >   	dp_display_enable(dp_display, 0);
> >   
> > --
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> > a Linux Foundation Collaborative Project