On Wed, Aug 31, 2011 at 01:44:20PM +0530, Thomas Abraham wrote:

There are two instances of clock with name i2c registered for s3c64xx.
One has a devname and the other does not. So this continued to work.
The i2c0 clock instance did not get a devname because its instance id
was -1 (prior to clkdev support).

Not having devname will *work* - the problem is that it'll work too
often and return the wrong clock whenever anything goes wrong.

If a devname is added to i2c0 clock instance for s3c64xx, it should be
set to "s3c2440-i2c". If the devname is set to "s3c2440-i2c.0", then
CONFIG_S3C_DEV_I2C1 will have to defined for s3c64xx, otherwise, as
per arch/arm/plat-samsung/dev-i2c0.c, the platform device id for i2c0
instance will be -1 and the clock lookup for i2c0 will fail.

All of which is just asking for fragility; the ifdefs for renumbering
the device are really unhelpful here - the system always has two I2C
controllers and the numbering is going to change depending on which
boards are built in so you can break things by enabling support for a
second board.

Frankly I'm not convinced that all this dancing about with explicitly
selecting which devices to enable is worth it; the space savings are
extremely small and the complexity regularly causes issues that just
shouldn't exist.