On 6/1/17 5:49 PM, Ian W MORRISON wrote: > On 31 May 2017 at 10:53, Doug Smythies <dsmyth...@telus.net> wrote: >> Note Before: >> I might not have the address list correct, as I have re-created this >> e-mail from the web page archive, having found the thread after bisecting the >> kernel. >> >> On 2017.05.29 18:50:57 -0400 (EDT) Mikulas Patocka wrote: >>> On Sun, 28 May 2017, Andy Lutomirski wrote: >>>> On Sun, May 28, 2017 at 11:18 AM, Bernhard Held <berny...@gmx.de> wrote: >>>>> Hi, >>>>> >>>>> this patch breaks the boot of my kernel. The last message is "Booting >>>>> the kernel.". >> >> It breaks my kernel boot also, and I know of at least two others with >> the same, or similar, problem as of kernel 4.12-rc3. >> > > Just to add that I cannot boot v4.12-rc3 kernel with any Intel Atom > (BYT and CHT) Intel Compute Sticks. Adding 'earlyprintk=efi' confirms > kernel panic with > [ 0.000000] Kernel panic - not syncing: x86/PAT: PAT enabled, but not > supported by secondary CPU > > > <snip> >
Confirmed that following patch fixes boot of v4.12-rc3 for Intel Atom Compute Sticks: [PATCH] Fix X86_FEATURE_PAT regression bug Early kernel panic caused by checking for X86_FEATURE_PAT when enabled but not supported by secondary CPU. Fixes cbed27cdf0e3 ("x86/PAT: Fix Xorg regression on CPUs that don't support PAT") Signed-off-by: Ian W Morrison <ianwmorri...@gmail.com> --- arch/x86/mm/pat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 83a59a6..c537bfb 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -234,7 +234,7 @@ static void pat_bsp_init(u64 pat) static void pat_ap_init(u64 pat) { - if (!this_cpu_has(X86_FEATURE_PAT)) { + if (!boot_cpu_has(X86_FEATURE_PAT)) { /* * If this happens we are on a secondary CPU, but switched to * PAT on the boot CPU. We have no way to undo PAT. -- 1.9.1