imxfb does not turn on automatically

[Fabio Estevam]

Hi Sascha,

On Mon, Jan 11, 2016 at 5:16 AM, Sascha Hauer <s.hauer at pengutronix.de> wrote:

> Unfortunately this LCD controller does not have an enable bit. The
> controller starts directly when the clocks are enabled. If the clocks
> are enabled when the controller is not yet programmed with proper
> register values then it just goes into some undefined state. What I
> suspect is that the clocks already were enabled before driver probe,
> presumably by the bootloader, so the controller is already in undefined
> state when entering Linux. Now by dis/enabling the ipg clock you
> effectively reset the controller. Since you have programmed it with
> valid register values in the mean time it starts working after this
> reset.
> To verify you could try to disable the LCDC related clock gates with
> direct register writes in drivers/clk/imx/clk-imx25.c.

Excellent! I did as you suggested and now the LCD turns on by default.

U-boot was enabling the LCD IPG clock.

Will submit a formal patch soon.

Thanks!