After tc358768_setup_pll() enables PLL_CKEN and the lock indicator comes up, the downstream DSI register sequence runs immediately. On TF700T this results in the bridge claiming PLL lock but producing no DSI video output: the panel powers up, the backlight comes on, but the framebuffer is never scanned out.
Insert a small settling delay between PLL setup and the rest of the attach. Suggested-by: Michele Brocco <[email protected]> Tested-by: Michele Brocco <[email protected]> # TF700T Signed-off-by: Svyatoslav Ryhel <[email protected]> --- drivers/video/bridge/tc358768.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/video/bridge/tc358768.c b/drivers/video/bridge/tc358768.c index 358004f30f2..9fa9631fdcc 100644 --- a/drivers/video/bridge/tc358768.c +++ b/drivers/video/bridge/tc358768.c @@ -488,6 +488,9 @@ static int tc358768_attach(struct udevice *dev) tc358768_setup_pll(dev); + /* Allow the PLL to settle */ + mdelay(20); + dsiclk = priv->dsiclk; hsbyteclk = dsiclk / 4; -- 2.51.0
