Messages in this thread Patch in this message | | | Subject | Re: [RESEND] Fast TSC calibration fails with v3.14-rc1 and later | From | joeyli <> | Date | Wed, 12 Mar 2014 12:00:07 +0800 |
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Hi Julian,
於 二,2014-03-11 於 18:15 +0100,Julian Wollrath 提到: > Am Tue, 11 Mar 2014 14:56:41 +0100 (CET) > schrieb Thomas Gleixner <tglx@linutronix.de>: > > > Ok, via bisecting I found commit > > > 73f7d1ca32638028e3271f54616773727e2f9f26 (see below) to be the one > > > that introduced this regression. > > > > Interesting. I have no idea what's going on. But maybe can the ACPI > > folks shed some light on it. >
My patch moved acpi_early_init() to before timekeeping_init() is for prepare the later using ACPI TAD to set system clock. I think that because acpi_early_init() setup SCI interrupt and enable acpi subsystem, it causes fast TSC calibration fail.
> I have absolutely no idea, if it is the right thing to do and why it > works, but the patch below fixes the problem. Thank you for your help. > > > Cheers, > Julian Wollrath > > From 7664f495039d93adfce073e58840a46549904f04 Mon Sep 17 00:00:00 2001 > From: Julian Wollrath <jwollrath@web.de> > Date: Tue, 11 Mar 2014 18:05:43 +0100 > Subject: [PATCH] Fix fast TSC calibration > > Since commit 73f7d1ca32638028e3271f54616773727e2f9f26 the fast TSC calibration > failed on a Thinkpad X121e with an AMD E450 APU. Moving acpi_early_init() after > late_time_init() fixes this. > > Signed-off-by: Julian Wollrath <jwollrath@web.de> > --- > init/main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/init/main.c b/init/main.c > index eb03090cdced..bf9d99148bd6 100644 > --- a/init/main.c > +++ b/init/main.c > @@ -561,7 +561,6 @@ asmlinkage void __init start_kernel(void) > init_timers(); > hrtimers_init(); > softirq_init(); > - acpi_early_init(); > timekeeping_init(); > time_init(); > sched_clock_postinit(); > @@ -609,6 +608,7 @@ asmlinkage void __init start_kernel(void) > numa_policy_init(); > if (late_time_init) > late_time_init(); > + acpi_early_init(); > sched_clock_init(); > calibrate_delay(); > pidmap_init();
The late_time_init() dependent on timekeeping_init(), if we don't want move acpi_early_init() before timekeeping_init() then just direct put it before efi_enter_virtual_mode() because we tested this changed.
This patch restricts the position to run acpi_early_init() before timekeeping_init() when only "CMOS RTC Not Present" bit set in FADT.
Could you please help to test it on your machine?
Thanks a lot! Joey Lee
>From 8ef4fff76dd2f50bef1e8eb9c96f3b0228a38401 Mon Sep 17 00:00:00 2001 From: Lee, Chun-Yi <jlee@suse.com> Date: Wed, 12 Mar 2014 11:36:32 +0800 Subject: [PATCH] ACPI / init: Run acpi_early_init() before timekeeping_init() when CMOS RTC Not Present bit set
This is a variant patch from Rafael J. Wysocki's ACPI / init: Run acpi_early_init() before efi_enter_virtual_mode()
According to Matt Fleming, if acpi_early_init() was executed before efi_enter_virtual_mode(), the EFI initialization could benefit from it, so Rafael's patch makes that happen.
And, later we want accessing ACPI TAD device to set system clock, so move acpi_early_init() before timekeeping_init() when "CMOS RTC Not Present" bit set. This position is also before efi_enter_virtual_mode().
Signed-off-by: Lee, Chun-Yi <jlee@suse.com> --- init/main.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/init/main.c b/init/main.c index eb03090..e1b69d2 100644 --- a/init/main.c +++ b/init/main.c @@ -561,7 +561,9 @@ asmlinkage void __init start_kernel(void) init_timers(); hrtimers_init(); softirq_init(); - acpi_early_init(); + if (acpi_gbl_FADT.header.revision >= 5 && + acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_CMOS_RTC) + acpi_early_init(); timekeeping_init(); time_init(); sched_clock_postinit(); @@ -613,6 +615,9 @@ asmlinkage void __init start_kernel(void) calibrate_delay(); pidmap_init(); anon_vma_init(); + if (!(acpi_gbl_FADT.header.revision >= 5 && + acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_CMOS_RTC)) + acpi_early_init(); #ifdef CONFIG_X86 if (efi_enabled(EFI_RUNTIME_SERVICES)) efi_enter_virtual_mode(); -- 1.6.4.2
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