2020-07-30 06:16:34

by Dilip Kota

Subject: [PATCH 1/1] x86/tsr: Fix tsc frequency enumeration failure on lightning mountain SoC

Frequency descriptor of Lightning Mountain SoC doesn't have all the
frequency entries so resulting in the below failure causing kernel hang.

[ 0.000000] Error MSR_FSB_FREQ index 15 is unknown
[ 0.000000] tsc: Fast TSC calibration failed

So, add all the frequency entries in the Lightning Mountain SoC frequency
descriptor.

Fixes: 0cc5359d8fd45 ("x86/cpu: Update init data for new Airmont CPU model")
Fixes: 812c2d7506fd ("x86/tsc_msr: Use named struct initializers")
Signed-off-by: Dilip Kota <[email protected]>
---
arch/x86/kernel/tsc_msr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c
index 4fec6f3a1858b2..c255e10e914aa5 100644
--- a/arch/x86/kernel/tsc_msr.c
+++ b/arch/x86/kernel/tsc_msr.c
@@ -136,7 +136,8 @@ static const struct freq_desc freq_desc_ann = {
/* 24 MHz crystal? : 24 * 13 / 4 = 78 MHz */
static const struct freq_desc freq_desc_lgm = {
.use_msr_plat = true,
- .freqs = { 78000, 78000, 78000, 78000, 78000, 78000, 78000, 78000 },
+ .freqs = { 78000, 78000, 78000, 78000, 78000, 78000, 78000, 78000, 78000,
+ 78000, 78000, 78000, 78000, 78000, 78000, 78000 },
.mask = 0x0f,
};

--
2.11.0

2020-07-30 07:58:36

by Andy Shevchenko

Subject: Re: [PATCH 1/1] x86/tsr: Fix tsc frequency enumeration failure on lightning mountain SoC

On Thu, Jul 30, 2020 at 9:16 AM Dilip Kota <[email protected]> wrote:
>
> Frequency descriptor of Lightning Mountain SoC doesn't have all the
> frequency entries so resulting in the below failure causing kernel hang.
>
> [ 0.000000] Error MSR_FSB_FREQ index 15 is unknown
> [ 0.000000] tsc: Fast TSC calibration failed
>
> So, add all the frequency entries in the Lightning Mountain SoC frequency
> descriptor.

While at this, can you confirm (with maybe good description and
documentation reference) that the numbers in that array are all
correct?

--
With Best Regards,
Andy Shevchenko

2020-07-30 09:52:42

by Dilip Kota

Subject: Re: [PATCH 1/1] x86/tsr: Fix tsc frequency enumeration failure on lightning mountain SoC

On 7/30/2020 3:57 PM, Andy Shevchenko wrote:
> While at this, can you confirm (with maybe good description and
> documentation reference) that the numbers in that array are all
> correct?

Sure, i will add the description.

Regards,
Dilip