Re: 4.14.9 doesn't boot (regression)

[Ingo Molnar <mingo@kernel.org>]

* Linus Torvalds <torvalds@linux-foundation.org> wrote:

> On Fri, Dec 29, 2017 at 3:14 AM, Toralf Förster <toralf.foerster@gmx.de> wrote:
> >
> > For the server the attached .config works fine but switching from
> > CONFIG_GENERIC_CPU to CONFIG_MCORE2 legt them hang at boot w/op any
> > messages. Similar picture at the desktop.
> 
> Ok, so there's another thread ("4.14.9 with CONFIG_MCORE2 fails to
> boot") about this same thing, but one thing to try is to see if it's
> just the
> 
>          cflags-$(CONFIG_MCORE2) += \
>                  $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
> 
> in arch/x86/Makefile that causes this.
> 
> The MCORE2 option does potentially have a few other effects (see
> arch/x86/Kconfig.cpu), but the first one to check might be just that
> compiler command line effect.
> 
> So if you can edit arch/x86/Makefile, and just make that say
> 
>         cflags-$(CONFIG_MCORE2) += $(call cc-option,-mtune=generic)
> 
> instead, and see if that makes a difference, that would narrow down
> the possible root cause of this problem.

Or, if it's more convenient, you can try Linus's suggestion by applying the patch 
below.

Thanks,

	Ingo

===========>

 arch/x86/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 3e73bc255e4e..1835752fffc9 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -127,8 +127,8 @@ else
         cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
         cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
 
-        cflags-$(CONFIG_MCORE2) += \
-                $(call cc-option,-march=core2,$(call cc-option,-mtune=generic))
+	cflags-$(CONFIG_MCORE2) += $(call cc-option,-mtune=generic)
+
 	cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
 		$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
         cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)