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

From: H. Peter Anvin
Date: Thu Jan 21 2016 - 18:47:28 EST

On 01/21/16 15:43, William Breathitt Gray wrote:
> 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.

Well, and as you can see from the build robot because a lot of those
drivers simply don't compile on 64-bit systems. If nothing else you
would have to push the 32-bit tests downward in the config dependency tree.