Re: hung bootup with "drm/radeon/kms: move radeon KMS on/off switch out of staging."

[Felipe Contreras <felipe.contreras@gmail.com>]

On Thu, Feb 4, 2010 at 11:23 PM, Andrew Morton
<akpm@linux-foundation.org> wrote:
> On Thu, 4 Feb 2010 22:05:59 +0100
> Ingo Molnar <mingo@elte.hu> wrote:
>> Regressions are not limited to 'same config' kernels, last i checked. If that
>> has changed (or if i'm misunderstanding it) then it would be nice to hear a
>> clarification about that from Linus.
>>
>> The way i understand it is that there are narrow exceptions from the
>> regression rules, such as completely new drivers for which there can be no
>> prior expectation of stability by users. (but for even them we are generally
>> on the safer side to list bugs in them as regressions as well - especially if
>> we expect many users to enable it.)
>>
>> AFAIK there's no exception for new sub-features of existing facilities or
>> drivers, even if it's default-disabled.
>>
>> This issue materially affects quite a few bugs i'm handling as a maintainer.
>> Many of them are under default-off config options - most new aspects to
>> existing code are introduced in such a way. It would remove quite a bit of
>> urgent-workload from my workflow if i could strike them from Rafael's list
>> and could deprioritize them as "plain bugs", to be fixed as time permits.
>>
>> IMHO it would be rather counter-productive to kernel quality if we did that
>> kind of regression-lawyering though.
>
> Yes, it's mainly semantics.
>
> From the user's point of view
>
> kernel N: boots, works, plays nethack
> kernel N+1: goes splat
>
> That kernel regressed for that user.  He'll shrug and will go back to
> kernel N and we lost an N+1 tester.  And the distros who ship N+1 get a
> lot of hack work to do.
>
> If the feature is this buggy, it was wrong to make it accessible in Kconfig.

That's why some features are marked as _experimental_ and disabled by
default. If the feature is not marked as such, then yeah, I would
consider it a regression.

-- 
Felipe Contreras