Re: [PATCH] base: isa: Remove X86_32 dependency

[William Breathitt Gray]

On 01/21/2016 02:40 PM, H. Peter Anvin wrote:
> CONFIG_ISA is mainly used to exclude drivers that are for ISA-specific
> devices.
> 
> However, PC/104 is indeed an actual ISA parallel bus, and as you say
> widely used in embedded systems.  However, I would like to see if there
> are anything hidden with !CONFIG_ISA which makes sense in PC104 systems.

My ultimate objective is to be able to use the ISA bus driver
(drivers/base/isa.c). This driver is conditionally compiled based on
CONFIG_ISA, which in turn depends on CONFIG_X86_32. Up until now, I've
been using platform_driver for my non-hotpluggable PC/104 devices, but
it appears that isa_driver is more appropriate; unfortunately, I have
CONFIG_X86_64 set, which prevents the compilation of drivers/base/isa.c
due to the CONFIG_X86_32 dependency.

I can alternatively create a patch to introduce a CONFIG_PC104 option.
This would allow the compilation of the ISA bus driver on either
CONFIG_ISA or CONFIG_PC104, thus allowing CONFIG_ISA to remain dependent
on CONFIG_X86_32. However, if the CONFIG_X86_32 dependency was
arbitrarily added to simply hide ISA functionality from newer
motherboards, perhaps the dependency should be removed.

William Breathitt Gray