On Thu, Apr 28, 2022 at 02:24:26AM -0400, Paul Gortmaker wrote: > A few months back I was doing a test build for "defconfig-like" COTS > hardware and happened to notice some pmc-atom stuff being built. Fine, > I thought - the defconfig isn't minimal - we all know that - what Kconfig > do I use to turn that off? Well, imagine my surprise when I found out > you couldn't turn it [Atom Power Management Controller] code off! Turning it off on BayTrail and CherryTrail devices will be devastating to the users' experience. And plenty of cheap tablets are exactly made on that SoCs. > Normally we all agree to not use "default y" unless unavoidable, but > somehow this was added as "def_bool y" which is even worse ; you can > see the Kconfig setting but there is *no* way you can turn it off. > > After investigating, I found no reason why the atom code couldn't be > opt-out with just minor changes that the original addition overlooked. > > And so this series addreses that. I tried to be sensitive to not > break any existing configs in the process, but the defconfig will > now intentionally be different and exclude this atom specific code. > > Using a defconfig on today's linux-next, here is the delta summary: > > $ ./scripts/bloat-o-meter -c ../pmc-atom-pre/vmlinux ../pmc-atom-post/vmlinux|grep add/remove > add/remove: 0/410 grow/shrink: 0/7 up/down: 0/-47659 (-47659) > add/remove: 0/105 grow/shrink: 0/1 up/down: 0/-6848 (-6848) > add/remove: 0/56 grow/shrink: 0/1 up/down: 0/-10155 (-10155) > > $ ./scripts/bloat-o-meter -c ../pmc-atom-pre/vmlinux ../pmc-atom-post/vmlinux|grep Total > Total: Before=13626994, After=13579335, chg -0.35% > Total: Before=3572137, After=3565289, chg -0.19% > Total: Before=1235335, After=1225180, chg -0.82% > > It is hard to reclaim anything against the inevitable growth in > footprint, so I'd say we should be glad to take whatever we can. > > Boot tested defconfig on today's linux-next on older non-atom COTS. I believe this needs an extensive test done by Hans who possesses a lot of problematic devices that require that module to be present. Note to all your patches, please, use --cc option instead of putting noisy lines in the each of the commit messages. For myself I created a "smart" script [1] to avoid bothering with that. Feel free to use, modify, send PRs back to improve. [1]: https://github.com/andy-shev/home-bin-tools/blob/master/ge2maintainer.sh -- With Best Regards, Andy Shevchenko
