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2012-03-23kernel-time: fix s/then/than/ spelling errorsJim Cromie1-1/+1
Use than for comparisons, like more than. CC: John Stultz <john.stultz@linaro.org> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2012-01-06Merge branch 'driver-core-next' into Linux 3.2Greg Kroah-Hartman1-18/+19
This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file, and it fixes the build error in the arch/x86/kernel/microcode_core.c file, that the merge did not catch. The microcode_core.c patch was provided by Stephen Rothwell <sfr@canb.auug.org.au> who was invaluable in the merge issues involved with the large sysdev removal process in the driver-core tree. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-12-19time/clocksource: Fix kernel-doc warningsKusanagi Kouichi1-3/+9
Fix various KernelDoc build warnings. Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp> Cc: John Stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20111219091320.0D5AF6FC03D@msa105.auone-net.jp Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-14clocksource: convert sysdev_class to a regular subsystemKay Sievers1-18/+19
After all sysdev classes are ported to regular driver core entities, the sysdev implementation will be entirely removed from the kernel. Cc: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-12-01clocksource: Fix bug with max_deferment margin calculationYang Honggang (Joseph)1-2/+2
In order to leave a margin of 12.5% we should >> 3 not >> 5. CC: stable@kernel.org Signed-off-by: Yang Honggang (Joseph) <eagle.rtlinux@gmail.com> [jstultz: Modified commit subject] Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-11-10clocksource: Avoid selecting mult values that might overflow when adjustedJohn Stultz1-10/+48
For some frequencies, the clocks_calc_mult_shift() function will unfortunately select mult values very close to 0xffffffff. This has the potential to overflow when NTP adjusts the clock, adding to the mult value. This patch adds a clocksource.maxadj value, which provides an approximation of an 11% adjustment(NTP limits adjustments to 500ppm and the tick adjustment is limited to 10%), which could be made to the clocksource.mult value. This is then used to both check that the current mult value won't overflow/underflow, as well as warning us if the timekeeping_adjust() code pushes over that 11% boundary. v2: Fix max_adjustment calculation, and improve WARN_ONCE messages. v3: Don't warn before maxadj has actually been set CC: Yong Zhang <yong.zhang0@gmail.com> CC: David Daney <ddaney.cavm@gmail.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Chen Jie <chenj@lemote.com> CC: zhangfx <zhangfx@lemote.com> CC: stable@kernel.org Reported-by: Chen Jie <chenj@lemote.com> Reported-by: zhangfx <zhangfx@lemote.com> Tested-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-09-13clocksource: Make watchdog reset locklessThomas Gleixner1-20/+18
KGDB needs to trylock watchdog_lock when trying to reset the clocksource watchdog after the system has been stopped to avoid a potential deadlock. When the trylock fails TSC usually becomes unstable. We can be more clever by using an atomic counter and checking it in the clocksource_watchdog callback. We restart the watchdog whenever the counter is > 0 and only decrement the counter when we ran through a full update cycle. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <johnstul@us.ibm.com> Acked-by: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1109121326280.2723@ionos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-06-16clocksource: Make watchdog robust vs. interruptionThomas Gleixner1-11/+13
The clocksource watchdog code is interruptible and it has been observed that this can trigger false positives which disable the TSC. The reason is that an interrupt storm or a long running interrupt handler between the read of the watchdog source and the read of the TSC brings the two far enough apart that the delta is larger than the unstable treshold. Move both reads into a short interrupt disabled region to avoid that. Reported-and-tested-by: Vernon Mauery <vernux@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org