x86/tsr: Fix tsc frequency enumeration bug on Lightning Mountain SoC
authorDilip Kota <eswara.kota@linux.intel.com>
Mon, 3 Aug 2020 07:56:36 +0000 (15:56 +0800)
committerIngo Molnar <mingo@kernel.org>
Thu, 6 Aug 2020 23:32:00 +0000 (01:32 +0200)
Frequency descriptor of Lightning Mountain SoC doesn't have all the
frequency entries so resulting in the below failure causing a kernel hang:

    Error MSR_FSB_FREQ index 15 is unknown
    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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/211c643ae217604b46cbec43a2c0423946dc7d2d.1596440057.git.eswara.kota@linux.intel.com
arch/x86/kernel/tsc_msr.c

index 4fec6f3..a654a9b 100644 (file)
@@ -133,10 +133,15 @@ static const struct freq_desc freq_desc_ann = {
        .mask = 0x0f,
 };
 
-/* 24 MHz crystal? : 24 * 13 / 4 = 78 MHz */
+/*
+ * 24 MHz crystal? : 24 * 13 / 4 = 78 MHz
+ * Frequency step for Lightning Mountain SoC is fixed to 78 MHz,
+ * so all the frequency entries are 78000.
+ */
 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,
 };