[PATCH v2] drm/bridge: adv7511: Attach to DSI host at probe time

From: Matt Redfearn
Date: Thu Jun 27 2019 - 11:18:11 EST

In contrast to all of the DSI panel drivers in drivers/gpu/drm/panel
which attach to the DSI host via mipi_dsi_attach() at probe time, the
ADV7533 bridge device does not. Instead it defers this to the point that
the upstream device connects to its bridge via drm_bridge_attach().
The generic Synopsys MIPI DSI host driver does not register it's own
drm_bridge until the MIPI DSI has attached. But it does not call
drm_bridge_attach() on the downstream device until the upstream device
has attached. This leads to a chicken and the egg failure and the DRM
pipeline does not complete.
Since all other mipi_dsi_device drivers call mipi_dsi_attach() in
probe(), make the adv7533 mipi_dsi_device do the same. This ensures that
the Synopsys MIPI DSI host registers it's bridge such that it is
available for the upstream device to connect to.

Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx>


Changes in v2:
Cleanup if adv7533_attach_dsi fails.

drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index e7ddd3e3db9..807827bd910 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -874,9 +874,6 @@ static int adv7511_bridge_attach(struct drm_bridge *bridge)
drm_connector_attach_encoder(&adv->connector, bridge->encoder);

- if (adv->type == ADV7533)
- ret = adv7533_attach_dsi(adv);
if (adv->i2c_main->irq)
regmap_write(adv->regmap, ADV7511_REG_INT_ENABLE(0),
@@ -1222,8 +1219,17 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)

adv7511_audio_init(dev, adv7511);
+ if (adv7511->type == ADV7533) {
+ ret = adv7533_attach_dsi(adv7511);
+ if (ret)
+ goto err_remove_bridge;
+ }
return 0;

+ drm_bridge_remove(&adv7511->bridge);
if (adv7511->cec_clk)