diff options
| author | David S. Miller <davem@davemloft.net> | 2008-07-05 23:08:07 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-07-05 23:08:07 -0700 |
| commit | ea2aca084ba82aaf7c148d04914ceed8758ce08a (patch) | |
| tree | dcb3f4f849cf48deac2dd3bafd5c2cd2f0e7dc79 /arch/x86/kernel/tsc_32.c | |
| parent | f3032be921cd126615ce3bfd7084e3d319f3f892 (diff) | |
| parent | c5a78ac00c400df29645e59938700301efb371d0 (diff) | |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
Documentation/feature-removal-schedule.txt
drivers/net/wan/hdlc_fr.c
drivers/net/wireless/iwlwifi/iwl-4965.c
drivers/net/wireless/iwlwifi/iwl3945-base.c
Diffstat (limited to 'arch/x86/kernel/tsc_32.c')
| -rw-r--r-- | arch/x86/kernel/tsc_32.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c index 068759db63dd..65b70637ad97 100644 --- a/arch/x86/kernel/tsc_32.c +++ b/arch/x86/kernel/tsc_32.c @@ -14,7 +14,10 @@ #include "mach_timer.h" -static int tsc_disabled; +/* native_sched_clock() is called before tsc_init(), so + we must start with the TSC soft disabled to prevent + erroneous rdtsc usage on !cpu_has_tsc processors */ +static int tsc_disabled = -1; /* * On some systems the TSC frequency does not @@ -402,25 +405,20 @@ void __init tsc_init(void) { int cpu; - if (!cpu_has_tsc || tsc_disabled) { - /* Disable the TSC in case of !cpu_has_tsc */ - tsc_disabled = 1; + if (!cpu_has_tsc || tsc_disabled > 0) return; - } cpu_khz = calculate_cpu_khz(); tsc_khz = cpu_khz; if (!cpu_khz) { mark_tsc_unstable("could not calculate TSC khz"); - /* - * We need to disable the TSC completely in this case - * to prevent sched_clock() from using it. - */ - tsc_disabled = 1; return; } + /* now allow native_sched_clock() to use rdtsc */ + tsc_disabled = 0; + printk("Detected %lu.%03lu MHz processor.\n", (unsigned long)cpu_khz / 1000, (unsigned long)cpu_khz % 1000); |