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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-11 19:13:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-11 19:13:40 -0800 |
| commit | 9fc5c3e3237e02a94f41cd1d2b4291593d29791d (patch) | |
| tree | c8823725b10bd4d36e9311ea392dfdecb4db7974 /init/calibrate.c | |
| parent | 541048a1d31399ccdda27346a37eae4a2ad55186 (diff) | |
| parent | 7c9c3a1e5fc8728e948b8fa3cbcfcfb86db3afda (diff) | |
| download | linux-9fc5c3e3237e02a94f41cd1d2b4291593d29791d.tar.bz2 | |
Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/intel config: Fix the APB_TIMER selection
x86/mrst: Add additional debug prints for pb_keys
x86/intel config: Revamp configuration to allow for Moorestown and Medfield
x86/intel/scu/ipc: Match the changes in the x86 configuration
x86/apb: Fix configuration constraints
x86: Fix INTEL_MID silly
x86/Kconfig: Cyclone-timer depends on x86-summit
x86: Reduce clock calibration time during slave cpu startup
x86/config: Revamp configuration for MID devices
x86/sfi: Kill the IRQ as id hack
Diffstat (limited to 'init/calibrate.c')
| -rw-r--r-- | init/calibrate.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/init/calibrate.c b/init/calibrate.c index 24df7976816c..5f117ca9e069 100644 --- a/init/calibrate.c +++ b/init/calibrate.c @@ -246,6 +246,19 @@ recalibrate: static DEFINE_PER_CPU(unsigned long, cpu_loops_per_jiffy) = { 0 }; +/* + * Check if cpu calibration delay is already known. For example, + * some processors with multi-core sockets may have all cores + * with the same calibration delay. + * + * Architectures should override this function if a faster calibration + * method is available. + */ +unsigned long __attribute__((weak)) __cpuinit calibrate_delay_is_known(void) +{ + return 0; +} + void __cpuinit calibrate_delay(void) { unsigned long lpj; @@ -265,6 +278,8 @@ void __cpuinit calibrate_delay(void) lpj = lpj_fine; pr_info("Calibrating delay loop (skipped), " "value calculated using timer frequency.. "); + } else if ((lpj = calibrate_delay_is_known())) { + ; } else if ((lpj = calibrate_delay_direct()) != 0) { if (!printed) pr_info("Calibrating delay using timer " |