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

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

<missed one comment>


On 7/11/2022 3:39 PM, Abhinav Kumar 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@xxxxxxxxxx>
> > ---
> >   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?
>
> > -
> >   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,

With dsi_mgr_bridge_enable/dsi_mgr_bridge_disable() removed, how will we 
handle conditions like below:

    /* 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;

Have you verified bonded_dsi with this change?

> >       .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?
>
>
> > -
> > -    /* 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?
>
> 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?
>
> > +
> >       return connector;
> >   }