Subject: Re: randconfig build error with next-20141001, in drivers/i2c/algos/i2c-algo-bit.c

From: Oliver Hartkopp <[email-masked]>
Date: Tue, 07 Oct 2014 10:58:25 +0200

On 10/06/2014 08:09 PM, Randy Dunlap wrote:
> On 10/06/14 10:39, Oliver Hartkopp wrote:

>> AFAICS there is 'just' a style problem as 'configs should not enable entire
>> subsystems'. But it finally is a correct and valid Kconfig, right?
> 
> Yes, right.

(..)

> In the unlikely case that I2C is not enabled, the user should have to enable
> it instead of a solitary driver enabling it.  IOW, if a subsystem is disabled,
> the user probably wanted it that way and a single driver should not override
> that setting.

Due to the fact that a change to 'depends on I2C' would make the config option
invisible (and therefore not selectable) in the case I2C was (unlikely)
disabled I would finally vote to leave it as-is.

The current Kconfig entry already contains a description that points to the
requirement to have I2C and I2C_ALGOBIT to be enabled to compile this driver:

config CAN_PEAK_PCIEC
	bool "PEAK PCAN-ExpressCard Cards"
	depends on CAN_PEAK_PCI
	select I2C
	select I2C_ALGOBIT
	default y
	---help---
	  Say Y here if you want to use a PCAN-ExpressCard from PEAK-System
	  Technik. This will also automatically select I2C and I2C_ALGO
	  configuration options.

AFAIK the PEAK PCAN-ExpressCard is usually used in x86 architecture Laptops,
so it's near to an academic discussion as x86 usually selects I2C ;-)

@Stephane: When updating the help text to introduce the PCAN-ExpressCard 34
support anyway you might probably add some more information *why* the I2C
support is needed (for CAN transceiver settings and status LED).

And /s/I2C_ALGO/I2C_ALGOBIT/ :-)

Tnx & best regards,
Oliver