x86/tsc_msr: Remove debugging messages

Debugging messages are not necessary after all of the
possible hardware failures that never occur.
Instead, this code can simply return 0.

This code also doesn't need to print in the success case.
tsc_init() already prints the TSC frequency,
and apic=debug is available if anybody really is
interested in printing the LAPIC frequency.

Signed-off-by: Len Brown <len.brown@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/cf03279a125b95dfa9b8d3d5b4a66de09cd04050.1466138954.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c
index 4ec5e560ed735fd42b7cbec57acfd118c7010b9e..f7ba44b89cc4bde2a69fea8e7ad991f9d8117423 100644 (file)
--- a/arch/x86/kernel/tsc_msr.c
+++ b/arch/x86/kernel/tsc_msr.c
@@ -76,9 +76,10 @@ static int match_cpu(u8 family, u8 model)
        (freq_desc_tables[cpu_index].freqs[freq_id])
 
 /*
- * Do MSR calibration only for known/supported CPUs.
+ * MSR-based CPU/TSC frequency discovery for certain CPUs.
  *
- * Returns the calibration value or 0 if MSR calibration failed.
+ * Set global "lapic_timer_frequency" to bus_clock_cycles/jiffy
+ * Return processor base frequency in KHz, or 0 on failure.
  */
 unsigned long try_msr_calibrate_tsc(void)
 {
@@ -100,31 +101,17 @@ unsigned long try_msr_calibrate_tsc(void)
                rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
                ratio = (hi >> 8) & 0x1f;
        }
-       pr_info("Maximum core-clock to bus-clock ratio: 0x%x\n", ratio);
-
-       if (!ratio)
-               goto fail;
 
        /* Get FSB FREQ ID */
        rdmsr(MSR_FSB_FREQ, lo, hi);
        freq_id = lo & 0x7;
        freq = id_to_freq(cpu_index, freq_id);
-       pr_info("Resolved frequency ID: %u, frequency: %u KHz\n",
-                               freq_id, freq);
-       if (!freq)
-               goto fail;
 
        /* TSC frequency = maximum resolved freq * maximum resolved bus ratio */
        res = freq * ratio;
-       pr_info("TSC runs at %lu KHz\n", res);
 
 #ifdef CONFIG_X86_LOCAL_APIC
        lapic_timer_frequency = (freq * 1000) / HZ;
-       pr_info("lapic_timer_frequency = %d\n", lapic_timer_frequency);
 #endif
        return res;
-
-fail:
-       pr_warn("Fast TSC calibration using MSR failed\n");
-       return 0;
 }