Re: Frame buffers and early i2c

From: Jean Delvare
Date: Mon Jun 09 2008 - 14:52:33 EST


On Mon, 9 Jun 2008 16:47:42 +0200, Uli Luckas wrote:
> I am in the process of trying out a display connected to a colibri board's
> pxa frame buffer device. The display's power supply is switch through i2c.
>
> In order to use the frame buffer console I have i2c and pxafb compiled in.
>
> By default, the pxafb driver get's initialized before the i2c bus causing the
> display power up to fail.
>
> What do i2c people think about changing the link order here?

Why don't you ask on the i2c mailing list? Cc added.

Personally I have no objection, but dependencies can be tricky so
you'll have to be careful. video is early in the link order at the
moment.

> What do other frame buffer drivers handle the absence of i2c during early
> boot?

Interestingly enough, they appear to do fine, despite the linking
order. Maybe because i2c_init is a subsys_initcall() while framebuffer
drivers are initialized with module_init()? Then I'm not sure why your
own driver has a problem there.

--
Jean Delvare
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