x86: don't use tsc_khz to calculate lpj if notsc is passed

Impact: fix udelay when "notsc" boot parameter is passed

With notsc passed on commandline, tsc may not be used for
udelays, make sure that we do not use tsc_khz to calculate
the lpj value in such cases.

Reported-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 62348e4fd8d1..2ef80e301925 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -813,10 +813,6 @@ void __init tsc_init(void)
                 cpu_khz = calibrate_cpu();
 #endif
 
-        lpj = ((u64)tsc_khz * 1000);
-        do_div(lpj, HZ);
-        lpj_fine = lpj;
-
         printk("Detected %lu.%03lu MHz processor.\n",
                         (unsigned long)cpu_khz / 1000,
                         (unsigned long)cpu_khz % 1000);
@@ -836,6 +832,10 @@ void __init tsc_init(void)
         /* now allow native_sched_clock() to use rdtsc */
         tsc_disabled = 0;
 
+        lpj = ((u64)tsc_khz * 1000);
+        do_div(lpj, HZ);
+        lpj_fine = lpj;
+
         use_tsc_delay();
         /* Check and install the TSC clocksource */
         dmi_check_system(bad_tsc_dmi_table);