Re: Autoselecting SPI for MEDIA_SUBDRV_AUTOSELECT?

From: Mauro Carvalho Chehab
Date: Fri Aug 22 2014 - 11:43:23 EST


Em Fri, 22 Aug 2014 18:17:22 +0300
Antti Palosaari <crope@xxxxxx> escreveu:

> Moikka!
>
> On 08/22/2014 06:00 PM, Jeff Mahoney wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > Hi Antti -
> >
> > Commit e4462ffc160 ([media] Kconfig: sub-driver auto-select SPI bus)
> > enables CONFIG_SPI globally for a driver that won't even be enabled in
> > many cases.
> >
> > Is there a reason USB_MSI2500 doesn't select SPI instead of
> > MEDIA_SUBDRV_AUTOSELECT?
>
> Nothing but I decided to set it similarly as I2C, another more common
> bus. IIRC same was for I2C_MUX too.
>
> You could still disable media subdriver autoselect and then disable SPI
> and select all the media drivers (excluding MSSi2500) manually.
>
> I have feeling that media auto-select was added to select everything
> needed for media.

No. Actually, it is meant to be used to select the features that are
needed for the devices that got selected.

Selecting I2C there is already a hack, as there are a couple of devices
that don't need it (like as102). Still, we're doing that, as there are
so few exceptions that, for the sake of cleaner Kconfig setup, it is
the best solution.

I2C_MUX is also a little of abuse today, as there are also few devices
that use it, but we should change it, as there are some good reasons
to stop using the current I2C gate control by an i2c_mux.

I don't think that selecting SPI belongs there. The best is to move it
to the very few drivers that use it.

Regards,
Mauro
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