[PATCH v2 4/4] drm/msm/dsi: switch to DRM_PANEL_BRIDGE

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Tue Jul 12 10:00:48 UTC 2022


On Tue, 12 Jul 2022 at 01:39, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
>
>
> On 7/11/2022 2:43 AM, Dmitry Baryshkov wrote:
> > Currently the DSI driver has two separate paths: one if the next device
> > in a chain is a bridge and another one if the panel is connected
> > directly to the DSI host. Simplify the code path by using panel-bridge
> > driver (already selected in Kconfig) and dropping support for
> > handling the panel directly.
> >
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> > ---
> >   drivers/gpu/drm/msm/dsi/dsi.c         |  38 +---
> >   drivers/gpu/drm/msm/dsi/dsi.h         |  14 +-
> >   drivers/gpu/drm/msm/dsi/dsi_host.c    |  25 ---
> >   drivers/gpu/drm/msm/dsi/dsi_manager.c | 264 ++------------------------
> >   4 files changed, 26 insertions(+), 315 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c
> > index 1625328fa430..3c53e28092db 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi.c
> > @@ -6,14 +6,6 @@
> >   #include "dsi.h"
> >   #include "dsi_cfg.h"
> >
> > -struct drm_encoder *msm_dsi_get_encoder(struct msm_dsi *msm_dsi)
> > -{
> > -     if (!msm_dsi || !msm_dsi_device_connected(msm_dsi))
> > -             return NULL;
> > -
> > -     return msm_dsi->encoder;
> > -}
>
> panel_bridge doesnt have the best_encoder method today.
> Today, this does not break anything for us.
> But, for future if we do need it, panel_bridge needs to be expanded to
> add that method?

We have a 1:1 between encoder and connector, so
drm_connector_get_single_encoder() works well in our case.

>
> > -
> >   bool msm_dsi_is_cmd_mode(struct msm_dsi *msm_dsi)
> >   {
> >       unsigned long host_flags = msm_dsi_host_get_mode_flags(msm_dsi->host);
> > @@ -220,7 +212,7 @@ int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
> >                        struct drm_encoder *encoder)
> >   {
> >       struct msm_drm_private *priv;
> > -     struct drm_bridge *ext_bridge;
> > +     struct drm_connector *connector;
> >       int ret;
> >
> >       if (WARN_ON(!encoder) || WARN_ON(!msm_dsi) || WARN_ON(!dev))
> > @@ -254,26 +246,12 @@ int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
> >               goto fail;
> >       }
> >
> > -     /*
> > -      * check if the dsi encoder output is connected to a panel or an
> > -      * external bridge. We create a connector only if we're connected to a
> > -      * drm_panel device. When we're connected to an external bridge, we
> > -      * assume that the drm_bridge driver will create the connector itself.
> > -      */
> > -     ext_bridge = msm_dsi_host_get_bridge(msm_dsi->host);
> > -
> > -     if (ext_bridge)
> > -             msm_dsi->connector =
> > -                     msm_dsi_manager_ext_bridge_init(msm_dsi->id);
> > -     else
> > -             msm_dsi->connector =
> > -                     msm_dsi_manager_connector_init(msm_dsi->id);
> > -
> > -     if (IS_ERR(msm_dsi->connector)) {
> > -             ret = PTR_ERR(msm_dsi->connector);
> > +     connector = msm_dsi_manager_ext_bridge_init(msm_dsi->id);
> > +
> > +     if (IS_ERR(connector)) {
> > +             ret = PTR_ERR(connector);
> >               DRM_DEV_ERROR(dev->dev,
> >                       "failed to create dsi connector: %d\n", ret);
> > -             msm_dsi->connector = NULL;
> >               goto fail;
> >       }
> >
> > @@ -287,12 +265,6 @@ int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
> >               msm_dsi->bridge = NULL;
> >       }
> >
> > -     /* don't destroy connector if we didn't make it */
> > -     if (msm_dsi->connector && !msm_dsi->external_bridge)
> > -             msm_dsi->connector->funcs->destroy(msm_dsi->connector);
> > -
> > -     msm_dsi->connector = NULL;
> > -
> >       return ret;
> >   }
> >
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi.h b/drivers/gpu/drm/msm/dsi/dsi.h
> > index 580a1e6358bf..41630b8f5358 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi.h
> > +++ b/drivers/gpu/drm/msm/dsi/dsi.h
> > @@ -12,7 +12,6 @@
> >   #include <drm/drm_bridge.h>
> >   #include <drm/drm_crtc.h>
> >   #include <drm/drm_mipi_dsi.h>
> > -#include <drm/drm_panel.h>
> >
> >   #include "msm_drv.h"
> >   #include "disp/msm_disp_snapshot.h"
> > @@ -49,8 +48,6 @@ struct msm_dsi {
> >       struct drm_device *dev;
> >       struct platform_device *pdev;
> >
> > -     /* connector managed by us when we're connected to a drm_panel */
> > -     struct drm_connector *connector;
> >       /* internal dsi bridge attached to MDP interface */
> >       struct drm_bridge *bridge;
> >
> > @@ -58,10 +55,8 @@ struct msm_dsi {
> >       struct msm_dsi_phy *phy;
> >
> >       /*
> > -      * panel/external_bridge connected to dsi bridge output, only one of the
> > -      * two can be valid at a time
> > +      * external_bridge connected to dsi bridge output
> >        */
> > -     struct drm_panel *panel;
> >       struct drm_bridge *external_bridge;
> >
> >       struct device *phy_dev;
> > @@ -76,7 +71,6 @@ struct msm_dsi {
> >   /* dsi manager */
> >   struct drm_bridge *msm_dsi_manager_bridge_init(u8 id);
> >   void msm_dsi_manager_bridge_destroy(struct drm_bridge *bridge);
> > -struct drm_connector *msm_dsi_manager_connector_init(u8 id);
> >   struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id);
> >   int msm_dsi_manager_cmd_xfer(int id, const struct mipi_dsi_msg *msg);
> >   bool msm_dsi_manager_cmd_xfer_trigger(int id, u32 dma_base, u32 len);
> > @@ -87,11 +81,9 @@ void msm_dsi_manager_tpg_enable(void);
> >   /* msm dsi */
> >   static inline bool msm_dsi_device_connected(struct msm_dsi *msm_dsi)
> >   {
> > -     return msm_dsi->panel || msm_dsi->external_bridge;
> > +     return msm_dsi->external_bridge;
> >   }
> >
> > -struct drm_encoder *msm_dsi_get_encoder(struct msm_dsi *msm_dsi);
> > -
> >   /* dsi host */
> >   struct msm_dsi_host;
> >   int msm_dsi_host_xfer_prepare(struct mipi_dsi_host *host,
> > @@ -116,9 +108,7 @@ int msm_dsi_host_set_display_mode(struct mipi_dsi_host *host,
> >                                 const struct drm_display_mode *mode);
> >   enum drm_mode_status msm_dsi_host_check_dsc(struct mipi_dsi_host *host,
> >                                           const struct drm_display_mode *mode);
> > -struct drm_panel *msm_dsi_host_get_panel(struct mipi_dsi_host *host);
> >   unsigned long msm_dsi_host_get_mode_flags(struct mipi_dsi_host *host);
> > -struct drm_bridge *msm_dsi_host_get_bridge(struct mipi_dsi_host *host);
> >   int msm_dsi_host_register(struct mipi_dsi_host *host);
> >   void msm_dsi_host_unregister(struct mipi_dsi_host *host);
> >   void msm_dsi_host_set_phy_mode(struct mipi_dsi_host *host,
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > index fb5ab6c718c8..5a18aa710d00 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > @@ -164,7 +164,6 @@ struct msm_dsi_host {
> >       struct msm_display_dsc_config *dsc;
> >
> >       /* connected device info */
> > -     struct device_node *device_node;
> >       unsigned int channel;
> >       unsigned int lanes;
> >       enum mipi_dsi_pixel_format format;
> > @@ -1721,8 +1720,6 @@ static int dsi_host_detach(struct mipi_dsi_host *host,
> >
> >       dsi_dev_detach(msm_host->pdev);
> >
> > -     msm_host->device_node = NULL;
> > -
> >       DBG("id=%d", msm_host->id);
> >       if (msm_host->dev)
> >               queue_work(msm_host->workqueue, &msm_host->hpd_work);
> > @@ -1988,16 +1985,6 @@ static int dsi_host_parse_dt(struct msm_dsi_host *msm_host)
> >               goto err;
> >       }
> >
> > -     /* Get panel node from the output port's endpoint data */
> > -     device_node = of_graph_get_remote_node(np, 1, 0);
> > -     if (!device_node) {
> > -             DRM_DEV_DEBUG(dev, "%s: no valid device\n", __func__);
> > -             ret = -ENODEV;
> > -             goto err;
> > -     }
> > -
> > -     msm_host->device_node = device_node;
> > -
> >       if (of_property_read_bool(np, "syscon-sfpb")) {
> >               msm_host->sfpb = syscon_regmap_lookup_by_phandle(np,
> >                                       "syscon-sfpb");
> > @@ -2678,23 +2665,11 @@ enum drm_mode_status msm_dsi_host_check_dsc(struct mipi_dsi_host *host,
> >       return MODE_OK;
> >   }
> >
> > -struct drm_panel *msm_dsi_host_get_panel(struct mipi_dsi_host *host)
> > -{
> > -     return of_drm_find_panel(to_msm_dsi_host(host)->device_node);
> > -}
> > -
> >   unsigned long msm_dsi_host_get_mode_flags(struct mipi_dsi_host *host)
> >   {
> >       return to_msm_dsi_host(host)->mode_flags;
> >   }
> >
> > -struct drm_bridge *msm_dsi_host_get_bridge(struct mipi_dsi_host *host)
> > -{
> > -     struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
> > -
> > -     return of_drm_find_bridge(msm_host->device_node);
> > -}
> > -
> >   void msm_dsi_host_snapshot(struct msm_disp_state *disp_state, struct mipi_dsi_host *host)
> >   {
> >       struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> > index cb84d185d73a..3970368e07d5 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
> > @@ -214,39 +214,26 @@ static void dsi_mgr_phy_disable(int id)
> >       }
> >   }
> >
> > -struct dsi_connector {
> > -     struct drm_connector base;
> > -     int id;
> > -};
> > -
> >   struct dsi_bridge {
> >       struct drm_bridge base;
> >       int id;
> >   };
> >
> > -#define to_dsi_connector(x) container_of(x, struct dsi_connector, base)
> >   #define to_dsi_bridge(x) container_of(x, struct dsi_bridge, base)
> >
> > -static inline int dsi_mgr_connector_get_id(struct drm_connector *connector)
> > -{
> > -     struct dsi_connector *dsi_connector = to_dsi_connector(connector);
> > -     return dsi_connector->id;
> > -}
> > -
> >   static int dsi_mgr_bridge_get_id(struct drm_bridge *bridge)
> >   {
> >       struct dsi_bridge *dsi_bridge = to_dsi_bridge(bridge);
> >       return dsi_bridge->id;
> >   }
> >
> > -static int msm_dsi_manager_panel_init(struct drm_connector *conn, u8 id)
> > +static void msm_dsi_manager_set_split_display(u8 id)
> >   {
> > -     struct msm_drm_private *priv = conn->dev->dev_private;
> > -     struct msm_kms *kms = priv->kms;
> >       struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> >       struct msm_dsi *other_dsi = dsi_mgr_get_other_dsi(id);
> > +     struct msm_drm_private *priv = msm_dsi->dev->dev_private;
> > +     struct msm_kms *kms = priv->kms;
> >       struct msm_dsi *master_dsi, *slave_dsi;
> > -     struct drm_panel *panel;
> >
> >       if (IS_BONDED_DSI() && !IS_MASTER_DSI_LINK(id)) {
> >               master_dsi = other_dsi;
> > @@ -256,89 +243,18 @@ static int msm_dsi_manager_panel_init(struct drm_connector *conn, u8 id)
> >               slave_dsi = other_dsi;
> >       }
> >
> > -     /*
> > -      * There is only 1 panel in the global panel list for bonded DSI mode.
> > -      * Therefore slave dsi should get the drm_panel instance from master
> > -      * dsi.
> > -      */
> > -     panel = msm_dsi_host_get_panel(master_dsi->host);
> > -     if (IS_ERR(panel)) {
> > -             DRM_ERROR("Could not find panel for %u (%ld)\n", msm_dsi->id,
> > -                       PTR_ERR(panel));
> > -             return PTR_ERR(panel);
> > -     }
> > -
> > -     if (!panel || !IS_BONDED_DSI())
> > -             goto out;
> > -
> > -     drm_object_attach_property(&conn->base,
> > -                                conn->dev->mode_config.tile_property, 0);
> > +     if (!msm_dsi->external_bridge || !IS_BONDED_DSI())
> > +             return;
> >
> >       /*
> >        * Set split display info to kms once bonded DSI panel is connected to
> >        * both hosts.
> >        */
> > -     if (other_dsi && other_dsi->panel && kms->funcs->set_split_display) {
> > +     if (other_dsi && other_dsi->external_bridge && kms->funcs->set_split_display) {
> >               kms->funcs->set_split_display(kms, master_dsi->encoder,
> >                                             slave_dsi->encoder,
> >                                             msm_dsi_is_cmd_mode(msm_dsi));
> >       }
> > -
> > -out:
> > -     msm_dsi->panel = panel;
> > -     return 0;
> > -}
> > -
> > -static enum drm_connector_status dsi_mgr_connector_detect(
> > -             struct drm_connector *connector, bool force)
> > -{
> > -     int id = dsi_mgr_connector_get_id(connector);
> > -     struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> > -
> > -     return msm_dsi->panel ? connector_status_connected :
> > -             connector_status_disconnected;
> > -}
> > -
> > -static void dsi_mgr_connector_destroy(struct drm_connector *connector)
> > -{
> > -     struct dsi_connector *dsi_connector = to_dsi_connector(connector);
> > -
> > -     DBG("");
> > -
> > -     drm_connector_cleanup(connector);
> > -
> > -     kfree(dsi_connector);
> > -}
> > -
> > -static int dsi_mgr_connector_get_modes(struct drm_connector *connector)
> > -{
> > -     int id = dsi_mgr_connector_get_id(connector);
> > -     struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> > -     struct drm_panel *panel = msm_dsi->panel;
> > -     int num;
> > -
> > -     if (!panel)
> > -             return 0;
> > -
> > -     /*
> > -      * In bonded DSI mode, we have one connector that can be
> > -      * attached to the drm_panel.
> > -      */
> > -     num = drm_panel_get_modes(panel, connector);
> > -     if (!num)
> > -             return 0;
> > -
> > -     return num;
> > -}
> > -
> > -static struct drm_encoder *
> > -dsi_mgr_connector_best_encoder(struct drm_connector *connector)
> > -{
> > -     int id = dsi_mgr_connector_get_id(connector);
> > -     struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> > -
> > -     DBG("");
> > -     return msm_dsi_get_encoder(msm_dsi);
> >   }
> >
> >   static void dsi_mgr_bridge_power_on(struct drm_bridge *bridge)
> > @@ -403,7 +319,6 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
> >       struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> >       struct msm_dsi *msm_dsi1 = dsi_mgr_get_dsi(DSI_1);
> >       struct mipi_dsi_host *host = msm_dsi->host;
> > -     struct drm_panel *panel = msm_dsi->panel;
> >       bool is_bonded_dsi = IS_BONDED_DSI();
> >       int ret;
> >
> > @@ -418,18 +333,6 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
> >       if (!dsi_mgr_power_on_early(bridge))
> >               dsi_mgr_bridge_power_on(bridge);
> >
> > -     /* Always call panel functions once, because even for dual panels,
> > -      * there is only one drm_panel instance.
> > -      */
> > -     if (panel) {
> > -             ret = drm_panel_prepare(panel);
> > -             if (ret) {
> > -                     pr_err("%s: prepare panel %d failed, %d\n", __func__,
> > -                                                             id, ret);
> > -                     goto panel_prep_fail;
> > -             }
> > -     }
> > -
> >       ret = msm_dsi_host_enable(host);
> >       if (ret) {
> >               pr_err("%s: enable host %d failed, %d\n", __func__, id, ret);
> > @@ -449,9 +352,6 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
> >   host1_en_fail:
> >       msm_dsi_host_disable(host);
> >   host_en_fail:
> > -     if (panel)
> > -             drm_panel_unprepare(panel);
> > -panel_prep_fail:
> >
> >       return;
> >   }
> > @@ -469,62 +369,12 @@ void msm_dsi_manager_tpg_enable(void)
> >       }
> >   }
> >
> > -static void dsi_mgr_bridge_enable(struct drm_bridge *bridge)
> > -{
> > -     int id = dsi_mgr_bridge_get_id(bridge);
> > -     struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> > -     struct drm_panel *panel = msm_dsi->panel;
> > -     bool is_bonded_dsi = IS_BONDED_DSI();
> > -     int ret;
> > -
> > -     DBG("id=%d", id);
> > -     if (!msm_dsi_device_connected(msm_dsi))
> > -             return;
> > -
> > -     /* Do nothing with the host if it is slave-DSI in case of bonded DSI */
> > -     if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id))
> > -             return;
> > -
> > -     if (panel) {
> > -             ret = drm_panel_enable(panel);
> > -             if (ret) {
> > -                     pr_err("%s: enable panel %d failed, %d\n", __func__, id,
> > -                                                                     ret);
> > -             }
> > -     }
> > -}
> > -
> > -static void dsi_mgr_bridge_disable(struct drm_bridge *bridge)
> > -{
> > -     int id = dsi_mgr_bridge_get_id(bridge);
> > -     struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> > -     struct drm_panel *panel = msm_dsi->panel;
> > -     bool is_bonded_dsi = IS_BONDED_DSI();
> > -     int ret;
> > -
> > -     DBG("id=%d", id);
> > -     if (!msm_dsi_device_connected(msm_dsi))
> > -             return;
> > -
> > -     /* Do nothing with the host if it is slave-DSI in case of bonded DSI */
> > -     if (is_bonded_dsi && !IS_MASTER_DSI_LINK(id))
> > -             return;
> > -
> > -     if (panel) {
> > -             ret = drm_panel_disable(panel);
> > -             if (ret)
> > -                     pr_err("%s: Panel %d OFF failed, %d\n", __func__, id,
> > -                                                                     ret);
> > -     }
> > -}
> > -
> >   static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge)
> >   {
> >       int id = dsi_mgr_bridge_get_id(bridge);
> >       struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> >       struct msm_dsi *msm_dsi1 = dsi_mgr_get_dsi(DSI_1);
> >       struct mipi_dsi_host *host = msm_dsi->host;
> > -     struct drm_panel *panel = msm_dsi->panel;
> >       bool is_bonded_dsi = IS_BONDED_DSI();
> >       int ret;
> >
> > @@ -551,13 +401,6 @@ static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge)
> >                       pr_err("%s: host1 disable failed, %d\n", __func__, ret);
> >       }
> >
> > -     if (panel) {
> > -             ret = drm_panel_unprepare(panel);
> > -             if (ret)
> > -                     pr_err("%s: Panel %d unprepare failed,%d\n", __func__,
> > -                                                             id, ret);
> > -     }
> > -
> >       msm_dsi_host_disable_irq(host);
> >       if (is_bonded_dsi && msm_dsi1)
> >               msm_dsi_host_disable_irq(msm_dsi1->host);
> > @@ -614,76 +457,13 @@ static enum drm_mode_status dsi_mgr_bridge_mode_valid(struct drm_bridge *bridge,
> >       return msm_dsi_host_check_dsc(host, mode);
> >   }
> >
> > -static const struct drm_connector_funcs dsi_mgr_connector_funcs = {
> > -     .detect = dsi_mgr_connector_detect,
> > -     .fill_modes = drm_helper_probe_single_connector_modes,
> > -     .destroy = dsi_mgr_connector_destroy,
> > -     .reset = drm_atomic_helper_connector_reset,
> > -     .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> > -     .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> > -};
> > -
> > -static const struct drm_connector_helper_funcs dsi_mgr_conn_helper_funcs = {
> > -     .get_modes = dsi_mgr_connector_get_modes,
> > -     .best_encoder = dsi_mgr_connector_best_encoder,
> > -};
> > -
> >   static const struct drm_bridge_funcs dsi_mgr_bridge_funcs = {
> >       .pre_enable = dsi_mgr_bridge_pre_enable,
> > -     .enable = dsi_mgr_bridge_enable,
> > -     .disable = dsi_mgr_bridge_disable,
> >       .post_disable = dsi_mgr_bridge_post_disable,
> >       .mode_set = dsi_mgr_bridge_mode_set,
> >       .mode_valid = dsi_mgr_bridge_mode_valid,
> >   };
> >
> > -/* initialize connector when we're connected to a drm_panel */
> > -struct drm_connector *msm_dsi_manager_connector_init(u8 id)
> > -{
> > -     struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
> > -     struct drm_connector *connector = NULL;
> > -     struct dsi_connector *dsi_connector;
> > -     int ret;
> > -
> > -     dsi_connector = kzalloc(sizeof(*dsi_connector), GFP_KERNEL);
> > -     if (!dsi_connector)
> > -             return ERR_PTR(-ENOMEM);
> > -
> > -     dsi_connector->id = id;
> > -
> > -     connector = &dsi_connector->base;
> > -
> > -     ret = drm_connector_init(msm_dsi->dev, connector,
> > -                     &dsi_mgr_connector_funcs, DRM_MODE_CONNECTOR_DSI);
> > -     if (ret)
> > -             return ERR_PTR(ret);
> > -
> > -     drm_connector_helper_add(connector, &dsi_mgr_conn_helper_funcs);
> > -
> > -     /* Enable HPD to let hpd event is handled
> > -      * when panel is attached to the host.
> > -      */
> > -     connector->polled = DRM_CONNECTOR_POLL_HPD;
>
> I see that this part gets removed with this migration.
>
> For fixed/built-in displays, it should not matter i think but i am not
> sure if some usermodes might expect this even for DSI?
>
> So, once again does panel_bridge needs to account for this?

Panel bridge sets only DRM_BRIDGE_OP_MODES. If you check the existing
code, the dsi_mgr_connector also does not provide HPD support. It only
can return panel status depending on whether the drm_panel was fetched
or not. No events are generated ever.
Thus said I think we should stop hijacking the usual mechanisms. If we
do not do the HPD, let's not declare it. If there is a case of panel
being hotplugged or switched, it will be handled by the next bridge in
the chain, not by the MSM DSI code.

>
>
> > -
> > -     /* Display driver doesn't support interlace now. */
> > -     connector->interlace_allowed = 0;
> > -     connector->doublescan_allowed = 0;
> > -
> > -     drm_connector_attach_encoder(connector, msm_dsi->encoder);
> > -
> > -     ret = msm_dsi_manager_panel_init(connector, id);
> > -     if (ret) {
> > -             DRM_DEV_ERROR(msm_dsi->dev->dev, "init panel failed %d\n", ret);
> > -             goto fail;
> > -     }
> > -
> > -     return connector;
> > -
> > -fail:
> > -     connector->funcs->destroy(connector);
> > -     return ERR_PTR(ret);
> > -}
> > -
> >   /* initialize bridge */
> >   struct drm_bridge *msm_dsi_manager_bridge_init(u8 id)
> >   {
> > @@ -732,8 +512,11 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
> >       int ret;
> >
> >       int_bridge = msm_dsi->bridge;
> > -     ext_bridge = msm_dsi->external_bridge =
> > -                     msm_dsi_host_get_bridge(msm_dsi->host);
> > +     ext_bridge = devm_drm_of_get_bridge(&msm_dsi->pdev->dev, msm_dsi->pdev->dev.of_node, 1, 0);
> > +     if (IS_ERR(ext_bridge))
> > +             return ERR_CAST(ext_bridge);
> > +
> > +     msm_dsi->external_bridge = ext_bridge;
> >
> >       encoder = msm_dsi->encoder;
> >
> > @@ -745,25 +528,12 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
> >       ret = drm_bridge_attach(encoder, ext_bridge, int_bridge,
> >                       DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> >       if (ret == -EINVAL) {
> > -             struct drm_connector *connector;
> > -             struct list_head *connector_list;
> > -
> >               /* link the internal dsi bridge to the external bridge */
> > -             drm_bridge_attach(encoder, ext_bridge, int_bridge, 0);
> > +             ret = drm_bridge_attach(encoder, ext_bridge, int_bridge, 0);
> > +             if (ret < 0)
> > +                     return ERR_PTR(ret);
> >
> > -             /*
> > -              * we need the drm_connector created by the external bridge
> > -              * driver (or someone else) to feed it to our driver's
> > -              * priv->connector[] list, mainly for msm_fbdev_init()
> > -              */
> > -             connector_list = &dev->mode_config.connector_list;
> > -
> > -             list_for_each_entry(connector, connector_list, head) {
> > -                     if (drm_connector_has_possible_encoder(connector, encoder))
> > -                             return connector;
> > -             }
> > -
> > -             return ERR_PTR(-ENODEV);
> > +             goto out;
> >       }
> >
> >       connector = drm_bridge_connector_init(dev, encoder);
> > @@ -774,6 +544,10 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
> >
> >       drm_connector_attach_encoder(connector, encoder);
> >
> > +out:
> > +     /* The pipeline is ready, ping encoders if necessary */
> > +     msm_dsi_manager_set_split_display(id);
> Do you still want to execute msm_dsi_manager_set_split_display even for
> the error case? Like in the above lines you have replaced the return
> ERR_PTR() with the goto out. But do you want to then move the
> set_split_display() call above the out label?

You see, the return ERR_PTR was the error case, where we could not
find the connector corresponding to the encoder.
We just don't need it anymore. Let's change the function to return int
rather than the unused connector.

>
> Also, now for the cases where there was an error where the connector was
> not found, we will return a NULL ptr instead of the ERR_PTR(-ENODEV).
> Is that expected?

Yes. We just do not care anymore about this connector.

>
> > +
> >       return connector;
> >   }
> >



-- 
With best wishes
Dmitry


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