Re: [PATCH v4] drm/msm/dp: do not initialize phy until plugin interrupt received

[Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>]

On 11/15/2021 12:23 PM, khsieh@xxxxxxxxxxxxxx wrote:
> On 2021-11-09 13:38, Kuogee Hsieh wrote:
> > From: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
> >
> > Current DP drivers have regulators, clocks, irq and phy are grouped
> > together within a function and executed not in a symmetric manner.
> > This increase difficulty of code maintenance and limited code 
> > scalability.
> > This patch divided the driver life cycle of operation into four states,
> > resume (including booting up), dongle plugin, dongle unplugged and 
> > suspend.
> > Regulators, core clocks and irq are grouped together and enabled at 
> > resume
> > (or booting up) so that the DP controller is armed and ready to 
> > receive HPD
> > plugin interrupts. HPD plugin interrupt is generated when a dongle plugs
> > into DUT (device under test). Once HPD plugin interrupt is received, DP
> > controller will initialize phy so that dpcd read/write will function and
> > following link training can be proceeded successfully. DP phy will be
> > disabled after main link is teared down at end of unplugged HPD 
> > interrupt
> > handle triggered by dongle unplugged out of DUT. Finally regulators, 
> > code
> > clocks and irq are disabled at corresponding suspension.
> >
> > 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
> >
> > Changes in V4:
> > -- rewording commit text to match this commit changes
> >
> > Fixes: e91e3065a806 ("drm/msm/dp: Add DP compliance tests on
> > Snapdragon Chipsets")
> >
> > Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> > ---
>
> any more comments?
Hi Stephen/Bjorn,

Any more comments?

We like to merge this patch by the end of this month.

Would you please give me your comments asap.

Thanks,

> >  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);