Subject: Re: linux-next: build failure in the staging tree (Was: kisskb: FAILED linux-next/s390-allmodconfig/s390x Mon Jul 31, 17:24)

From: Laurentiu Tudor <[email-masked]>
Date: Tue, 1 Aug 2017 08:29:31 +0000

On 07/31/2017 06:58 PM, Greg KH wrote:
> On Mon, Jul 31, 2017 at 09:55:14AM +0000, Laurentiu Tudor wrote:
>> Hi Stephen,
>>
>> That's because the fsl-mc driver selects GENERIC_MSI_IRQ_DOMAIN and not
>> all arches implement the support for the option. I can submit a patch
>> that adds explicit dependencies on arches that it was build-tested (x86,
>> arm, powerpc, all both 32 and 64 bits) similar to how it's done here
>> [1]. Let me know if you're ok with this fix and i'll submit the fix to
>> staging.
>
> Ugh, you should not be selecting that option, but rather depending on
> the option, right?

All users in the kernel use "select", so i don't think so. An 
interesting use that adds explicit dependencies on architectures can be
seen here [1], in the generic code. I've proposed a patch [2] that does 
a similar thing for mc-bus. I think it's a good approach as it keeps 
things under control by explicitly specifying the architectures on which
the driver was compile-tested.

---
Best Regards, Laurentiu

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/Kconfig#n28
[2] https://patchwork.kernel.org/patch/9871861/