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

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

[Dilip Kota]

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 <eswara.kota@linux.intel.com>
---
 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

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

[Andy Shevchenko]

On Thu, Jul 30, 2020 at 9:16 AM Dilip Kota <eswara.kota@linux.intel.com> 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

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

[Dilip Kota]

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