Re: [PATCH 04/30] drm/bridge/tc358767: Don't register DP AUX channel until bridge is attached

Hey Lyude,

This patch looks good to me.

Reviewed-by: Robert Foss robert.foss@linaro.org

On Fri, 19 Feb 2021 at 22:56, Lyude Paul lyude@redhat.com wrote:

Since this is a bridge, we don't start out with a respective DRM device. Likewise this means we don't have a connector, which also means that we should be following drm_dp_aux_register()'s documentation advice and not call drm_dp_aux_register() until we have a matching connector. Instead, call drm_dp_aux_init() in tc_probe() and wait until tc_bridge_attach() to register our AUX channel. We also add tc_bridge_detach() to handle unregistering the AUX adapter once the bridge has been disconnected.

Signed-off-by: Lyude Paul lyude@redhat.com

drivers/gpu/drm/bridge/tc358767.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 34a3e4e9f717..da89922721ed 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -1414,11 +1414,15 @@ static int tc_bridge_attach(struct drm_bridge *bridge, if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) return 0;

•   ret = drm_dp_aux_register(&tc->aux);
  

•   if (ret < 0)
  

•           return ret;
  

•   /* Create DP/eDP connector */
    drm_connector_helper_add(&tc->connector, &tc_connector_helper_funcs);
    ret = drm_connector_init(drm, &tc->connector, &tc_connector_funcs, tc->bridge.type);
    if (ret)
  

•           return ret;
  

•           goto aux_unregister;
  
    /* Don't poll if don't have HPD connected */
    if (tc->hpd_pin >= 0) {
  

@@ -1438,10 +1442,19 @@ static int tc_bridge_attach(struct drm_bridge *bridge, drm_connector_attach_encoder(&tc->connector, tc->bridge.encoder);

    return 0;

+aux_unregister:

•   drm_dp_aux_unregister(&tc->aux);
  

•   return ret;
  

+}

+static void tc_bridge_detach(struct drm_bridge *bridge) +{

•   drm_dp_aux_unregister(&bridge_to_tc(bridge)->aux);
  

}

static const struct drm_bridge_funcs tc_bridge_funcs = { .attach = tc_bridge_attach,

•   .detach = tc_bridge_detach,
    .mode_valid = tc_mode_valid,
    .mode_set = tc_bridge_mode_set,
    .enable = tc_bridge_enable,
  

@@ -1680,9 +1693,7 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) tc->aux.name = "TC358767 AUX i2c adapter"; tc->aux.dev = tc->dev; tc->aux.transfer = tc_aux_transfer;

•   ret = drm_dp_aux_register(&tc->aux);
  

•   if (ret)
  

•           return ret;
  

•   drm_dp_aux_init(&tc->aux);
  
    tc->bridge.funcs = &tc_bridge_funcs;
    if (tc->hpd_pin >= 0)
  

@@ -1702,7 +1713,6 @@ static int tc_remove(struct i2c_client *client) struct tc_data *tc = i2c_get_clientdata(client);

    drm_bridge_remove(&tc->bridge);

•   drm_dp_aux_unregister(&tc->aux);
  
    return 0;
  

}

2.29.2