[patch 19/49] x86: dont use tsc_khz to calculate lpj if notsc ispassed

[Greg KH]

2.6.27-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Alok Kataria <akataria@xxxxxxxxxx>

commit 70de9a97049e0ba79dc040868564408d5ce697f9 upstream

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@xxxxxxxxx>
Signed-off-by: Alok N Kataria <akataria@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/x86/kernel/tsc.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -639,10 +639,6 @@ 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);
@@ -662,6 +658,10 @@ 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);

-- 
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