Re: [RFC PATCH v2 1/3] drm/bridge: cadence: cdns-mhdp8546-core: Remove legacy support for connector initialisation in bridge

[Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>]

Hi,

On 27/05/2025 11:41, Jayesh Choudhary wrote:
> Hello Tomi,
> 
> On 27/05/25 13:08, Tomi Valkeinen wrote:
>> Hi,
>>
>> On 21/05/2025 10:32, Jayesh Choudhary wrote:
>>> Now that we have DBANC framework, remove the connector initialisation
>>> code
>>> as that piece of code is not called if DRM_BRIDGE_ATTACH_NO_CONNECTOR
>>> flag
>>> is used. Only TI K3 platforms consume this driver and tidss (their
>>> display
>>> controller) has this flag set. So this legacy support can be dropped.
>>>
>>
>> Why is the series RFC? Does it not work? Is there something here you're
>> not comfortable with?
> 
> These changes work without any issue.
> 
> I was a little doubtful about the second patch so kept it as RFC.

You should explain why the series/patch is RFC, unless it's somehow
obvious. In this series I didn't see any TODOs or open questions or
anything.

>>
>>> Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
>>> ---
>>>   .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 186 +++---------------
>>>   1 file changed, 25 insertions(+), 161 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/
>>> drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>>> index b431e7efd1f0..66bd916c2fe9 100644
>>> --- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>>> +++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
>>> @@ -1444,56 +1444,6 @@ static const struct drm_edid
>>> *cdns_mhdp_edid_read(struct cdns_mhdp_device *mhdp,
>>>       return drm_edid_read_custom(connector,
>>> cdns_mhdp_get_edid_block, mhdp);
>>>   }
>>>   -static int cdns_mhdp_get_modes(struct drm_connector *connector)
>>> -{
>>> -    struct cdns_mhdp_device *mhdp = connector_to_mhdp(connector);
>>> -    const struct drm_edid *drm_edid;
>>> -    int num_modes;
>>> -
>>> -    if (!mhdp->plugged)
>>> -        return 0;
>>> -
>>> -    drm_edid = cdns_mhdp_edid_read(mhdp, connector);
>>> -
>>> -    drm_edid_connector_update(connector, drm_edid);
>>> -
>>> -    if (!drm_edid) {
>>> -        dev_err(mhdp->dev, "Failed to read EDID\n");
>>> -        return 0;
>>> -    }
>>> -
>>> -    num_modes = drm_edid_connector_add_modes(connector);
>>> -    drm_edid_free(drm_edid);
>>> -
>>> -    /*
>>> -     * HACK: Warn about unsupported display formats until we deal
>>> -     *       with them correctly.
>>> -     */
>>> -    if (connector->display_info.color_formats &&
>>> -        !(connector->display_info.color_formats &
>>> -          mhdp->display_fmt.color_format))
>>> -        dev_warn(mhdp->dev,
>>> -             "%s: No supported color_format found (0x%08x)\n",
>>> -            __func__, connector->display_info.color_formats);
>>> -
>>> -    if (connector->display_info.bpc &&
>>> -        connector->display_info.bpc < mhdp->display_fmt.bpc)
>>> -        dev_warn(mhdp->dev, "%s: Display bpc only %d < %d\n",
>>> -             __func__, connector->display_info.bpc,
>>> -             mhdp->display_fmt.bpc);
>>> -
>>> -    return num_modes;
>>> -}
>>> -
>>> -static int cdns_mhdp_connector_detect(struct drm_connector *conn,
>>> -                      struct drm_modeset_acquire_ctx *ctx,
>>> -                      bool force)
>>> -{
>>> -    struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
>>> -
>>> -    return cdns_mhdp_detect(mhdp);
>>> -}
>>> -
>>>   static u32 cdns_mhdp_get_bpp(struct cdns_mhdp_display_fmt *fmt)
>>>   {
>>>       u32 bpp;
>>> @@ -1547,114 +1497,6 @@ bool cdns_mhdp_bandwidth_ok(struct
>>> cdns_mhdp_device *mhdp,
>>>       return true;
>>>   }
>>>   -static
>>> -enum drm_mode_status cdns_mhdp_mode_valid(struct drm_connector *conn,
>>> -                      const struct drm_display_mode *mode)
>>> -{
>>> -    struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
>>> -
>>> -    mutex_lock(&mhdp->link_mutex);
>>> -
>>> -    if (!cdns_mhdp_bandwidth_ok(mhdp, mode, mhdp->link.num_lanes,
>>> -                    mhdp->link.rate)) {
>>> -        mutex_unlock(&mhdp->link_mutex);
>>> -        return MODE_CLOCK_HIGH;
>>> -    }
>>> -
>>> -    mutex_unlock(&mhdp->link_mutex);
>>> -    return MODE_OK;
>>> -}
>>> -
>>> -static int cdns_mhdp_connector_atomic_check(struct drm_connector *conn,
>>> -                        struct drm_atomic_state *state)
>>> -{
>>> -    struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
>>> -    struct drm_connector_state *old_state, *new_state;
>>> -    struct drm_crtc_state *crtc_state;
>>> -    u64 old_cp, new_cp;
>>> -
>>> -    if (!mhdp->hdcp_supported)
>>> -        return 0;
>>> -
>>> -    old_state = drm_atomic_get_old_connector_state(state, conn);
>>> -    new_state = drm_atomic_get_new_connector_state(state, conn);
>>> -    old_cp = old_state->content_protection;
>>> -    new_cp = new_state->content_protection;
>>> -
>>> -    if (old_state->hdcp_content_type != new_state->hdcp_content_type &&
>>> -        new_cp != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
>>> -        new_state->content_protection =
>>> DRM_MODE_CONTENT_PROTECTION_DESIRED;
>>> -        goto mode_changed;
>>> -    }
>>> -
>>> -    if (!new_state->crtc) {
>>> -        if (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
>>> -            new_state->content_protection =
>>> DRM_MODE_CONTENT_PROTECTION_DESIRED;
>>> -        return 0;
>>> -    }
>>> -
>>> -    if (old_cp == new_cp ||
>>> -        (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
>>> -         new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED))
>>> -        return 0;
>>> -
>>> -mode_changed:
>>> -    crtc_state = drm_atomic_get_new_crtc_state(state, new_state->crtc);
>>> -    crtc_state->mode_changed = true;
>>> -
>>> -    return 0;
>>> -}
>>> -
>>> -static const struct drm_connector_helper_funcs
>>> cdns_mhdp_conn_helper_funcs = {
>>> -    .detect_ctx = cdns_mhdp_connector_detect,
>>> -    .get_modes = cdns_mhdp_get_modes,
>>> -    .mode_valid = cdns_mhdp_mode_valid,
>>> -    .atomic_check = cdns_mhdp_connector_atomic_check,
>>> -};
>>> -
>>> -static const struct drm_connector_funcs cdns_mhdp_conn_funcs = {
>>> -    .fill_modes = drm_helper_probe_single_connector_modes,
>>> -    .atomic_duplicate_state =
>>> drm_atomic_helper_connector_duplicate_state,
>>> -    .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>>> -    .reset = drm_atomic_helper_connector_reset,
>>> -    .destroy = drm_connector_cleanup,
>>> -};
>>> -
>>> -static int cdns_mhdp_connector_init(struct cdns_mhdp_device *mhdp)
>>> -{
>>> -    u32 bus_format = MEDIA_BUS_FMT_RGB121212_1X36;
>>> -    struct drm_connector *conn = &mhdp->connector;
>>> -    struct drm_bridge *bridge = &mhdp->bridge;
>>> -    int ret;
>>> -
>>> -    conn->polled = DRM_CONNECTOR_POLL_HPD;
>>> -
>>> -    ret = drm_connector_init(bridge->dev, conn, &cdns_mhdp_conn_funcs,
>>> -                 DRM_MODE_CONNECTOR_DisplayPort);
>>> -    if (ret) {
>>> -        dev_err(mhdp->dev, "Failed to initialize connector with
>>> drm\n");
>>> -        return ret;
>>> -    }
>>> -
>>> -    drm_connector_helper_add(conn, &cdns_mhdp_conn_helper_funcs);
>>> -
>>> -    ret = drm_display_info_set_bus_formats(&conn->display_info,
>>> -                           &bus_format, 1);
>>> -    if (ret)
>>> -        return ret;
>>> -
>>> -    ret = drm_connector_attach_encoder(conn, bridge->encoder);
>>> -    if (ret) {
>>> -        dev_err(mhdp->dev, "Failed to attach connector to encoder\n");
>>> -        return ret;
>>> -    }
>>> -
>>> -    if (mhdp->hdcp_supported)
>>> -        ret = drm_connector_attach_content_protection_property(conn,
>>> true);
>>> -
>>> -    return ret;
>>> -}
>>> -
>>>   static int cdns_mhdp_attach(struct drm_bridge *bridge,
>>>                   struct drm_encoder *encoder,
>>>                   enum drm_bridge_attach_flags flags)
>>> @@ -1671,9 +1513,11 @@ static int cdns_mhdp_attach(struct drm_bridge
>>> *bridge,
>>>           return ret;
>>>         if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
>>> -        ret = cdns_mhdp_connector_init(mhdp);
>>> -        if (ret)
>>> -            goto aux_unregister;
>>> +        ret = -EINVAL;
>>> +        dev_err(mhdp->dev,
>>> +            "Connector initialisation not supported in bridge_attach
>>> %d\n",
>>> +            ret);
>>> +        goto aux_unregister;
>>>       }
>>>         spin_lock(&mhdp->start_lock);
>>> @@ -2158,6 +2002,25 @@ static const struct drm_edid
>>> *cdns_mhdp_bridge_edid_read(struct drm_bridge *brid
>>>       return cdns_mhdp_edid_read(mhdp, connector);
>>>   }
>>>   +static enum drm_mode_status
>>> +cdns_mhdp_bridge_mode_valid(struct drm_bridge *bridge,
>>> +                const struct drm_display_info *info,
>>> +                const struct drm_display_mode *mode)
>>> +{
>>> +    struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
>>> +
>>> +    mutex_lock(&mhdp->link_mutex);
>>> +
>>> +    if (!cdns_mhdp_bandwidth_ok(mhdp, mode, mhdp->link.num_lanes,
>>> +                    mhdp->link.rate)) {
>>> +        mutex_unlock(&mhdp->link_mutex);
>>> +        return MODE_CLOCK_HIGH;
>>> +    }
>>> +
>>> +    mutex_unlock(&mhdp->link_mutex);
>>> +    return MODE_OK;
>>> +}
>>> +
>>>   static const struct drm_bridge_funcs cdns_mhdp_bridge_funcs = {
>>>       .atomic_enable = cdns_mhdp_atomic_enable,
>>>       .atomic_disable = cdns_mhdp_atomic_disable,
>>> @@ -2172,6 +2035,7 @@ static const struct drm_bridge_funcs
>>> cdns_mhdp_bridge_funcs = {
>>>       .edid_read = cdns_mhdp_bridge_edid_read,
>>>       .hpd_enable = cdns_mhdp_bridge_hpd_enable,
>>>       .hpd_disable = cdns_mhdp_bridge_hpd_disable,
>>> +    .mode_valid = cdns_mhdp_bridge_mode_valid,
>>>   };
>>>     static bool cdns_mhdp_detect_hpd(struct cdns_mhdp_device *mhdp,
>>> bool *hpd_pulse)
>>
>> Why do you need to add bridge mode_valid() when removing the legacy
>> non-DRM_BRIDGE_ATTACH_NO_CONNECTOR code?
> 
> Okay. Then I will add the bridge mode_valid as a separate patch.

Well, it was a question =). But indeed my thought was that it sounded
like material for a separate patch. Is it more of a fix for the
DRM_BRIDGE_ATTACH_NO_CONNECTOR case?

 Tomi