Messages in this thread | | | Date | Thu, 05 Feb 2009 11:14:23 -0800 | From | Randy Dunlap <> | Subject | Re: 2.6.29-rc3-git6: Reported regressions from 2.6.28 |
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Ingo Molnar wrote: > * Randy Dunlap <randy.dunlap@oracle.com> wrote: > >> Eric Anholt wrote: >>> On Wed, 2009-02-04 at 19:56 +0100, Ingo Molnar wrote: >>>> * Linus Torvalds <torvalds@linux-foundation.org> wrote: >>>> >>>>> On Wed, 4 Feb 2009, Norbert Preining wrote: >>>>>> The problem is that if you have a configuration under 2.6.28 without >>>>>> CONFIG_FB and just call make oldconfig, or even make config and don't >>>>>> know that you loose the DRM. And I was using make oldconfig (there is a >>>>>> graphical config?? ;-)) >>>>> Sure. It's inconvenient, no question about that. I asked the i915 people >>>>> to look into not requiring CONFIG_FB, and I hope they will, but my point >>>>> is that I don't think we can consider "small one-time inconvenience" to be >>>>> a "regression". >>>> if you mean that as a general principle, there's four very real downsides in >>>> my opinion. >>>> >>>> Firstly, we could have done better (and still can do better), via various >>>> easy and non-intrusive measures: >>>> >>>> - We could add a runtime warning: >>>> >>>> for example a WARN_ONCE("please enable CONFIG_DRM_I915 and CONFIG_FB") >>>> that there's no DRM because CONFIG_FB is not selected and oldconfig >>>> loses the I915 setting silently - placed in a key DRM ioctl, would >>>> have gone a long way addressing the issue. Testers do notice kernel >>>> warnings that pop up when their X gets slow. (This approach might also >>>> have the added bonus of warning folks who enable the wrong driver for >>>> the hardware.) >>>> >>>> - Or we could add a more thoughtful Kconfig migration: >>>> >>>> Rename DRM_I915 to DRM_I915_FB [which it really is now], and keep >>>> DRM_I915 as a non-interactive migration helper: if set, it >>>> auto-selects both FB and DRM_I915_FB. >>>> >>>> While CONFIG_FB is an interactive Kconfig option so a select can be >>>> dangerous to a correct dependency tree, it seems safe to do in this >>>> specific case because it seems to be a rather leaf entry with no >>>> dependencies. >>> I tried select FB. It's the right thing to do. It doesn't work. I >>> posted to the mailing list two weeks ago about the insane dependency >>> chain that kbuild comes up with and fails on when we do this, and got >>> silence. >> I tried what you had described in that email (from 2 weeks ago), got the >> same results that you did, but kbuild does seem very confused (to me). >> >> reference email from 2+ weeks ago: >> http://marc.info/?l=linux-kernel&m=123197341316461&w=2 >> >> Adding Sam to cc. > > Check the patch i posted in this thread earlier today, it solves this > problem.
I saw it. I'd rather kconfig be fixed instead, if possible.
-- ~Randy
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