Re: [PATCH, RFC] Earlier I2C initialization

From: Jean Delvare
Date: Wed Jun 11 2008 - 05:15:31 EST


Hi Russell,

On Wed, 11 Jun 2008 10:00:16 +0100, Russell King - ARM Linux wrote:
> On Wed, Jun 11, 2008 at 10:11:30AM +0200, Jean Delvare wrote:
> > Hi David,
> >
> > On Tue, 10 Jun 2008 13:55:07 -0700, David Brownell wrote:
> > > > Why don't you simply initialize the drivers in question with
> > > > subsys_initcall()? That's what i2c-pnx, i2c-omap, i2c-davinci and
> > > > tps65010 are doing at the moment.
> > >
> > > If they happen to sit outside the I2C tree and *before* it in
> > > link order, things will misbehave.
> >
> > Well, i2c system bus drivers shouldn't sit outside of the I2C tree, so
> > that's not a problem. If you start accepting that drivers live at
> > random places in the source tree, then there's simply no way to get
> > things right.
>
> That's simply not a realistic view. As I've already pointed out,
> framebuffer devices have I2C busses for reading the DDC information
> from monitors. These I2C bus drivers live in drivers/video.
>
> Video grabbers have I2C busses for controlling, eg, tuners and video
> decoders. These live in drivers/media.
>
> If I follow your argument, would you like cyber2000fb.c to be moved
> entirely from drivers/video into drivers/i2c/busses because it contains
> an i2c bus driver? Clearly not.

Please read what I wrote again. I said: I2C SYSTEM BUS drivers should
live under drivers/i2c. DDC channels on graphics adapters and I2C buses
on multimedia adapters definitely do not qualify as system buses (and
don't need to be initialized early, either.)

Thanks,
--
Jean Delvare
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