On Wed, May 29, 2013 at 06:08:18PM -0700, John Stultz wrote: > On 05/29/2013 01:41 PM, Jens Taprogge wrote: > >On Tue, May 28, 2013 at 12:51:19PM -0700, John Stultz wrote: > >>On 05/26/2013 12:25 PM, Jens Taprogge wrote: > >>>Hi all. > >>> > >>>Linux 3.9.3 hangs early during boot on a Lenovo Thinkpad X1 Carbon (Ivy > >>>Bridge). v3.9.2 works. I have bisected the hang to > >>> d96ac6f2: time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitons. > >>> > >>>Reverting d96ac6f2 on top of v3.9.4 makes the kernel boot. I do not > >>>have any additional information as the kernel hangs before anything is > >>>displayed. The config of v3.9.4 with d96ac6f2 reverted is attached. > >>So with 3.9.4 (nothing reverted), what was the config you were using > >>to boot? > >> > >>Does changing CONFIG_RTC_HCTOSYS change the behavior? > >> > >>thanks > >>-john > >Hello John, > > > >turns out things behave quite differently with the patch reverted and > >not reverted. Since there is no output, I can not tell whether I am > >seeing one or two problems. > > > >With vanilla 3.9.4: > > > > CONFIG_RTC_HCTOSYS=y works > > CONFIG_RTC_HCTOSYS=n does not work > > Huh. Strange, I actually was expecting the opposite. > > The odd thing is, commit d96ac6f2 *allows* HCTOSYS=y to be set. In > other words, without that patch, HCTOSYS is always N. > > So its weird HCTOSYS=y works, but also reverting the patch (which > forces HCTOSYS=N) works. > > Still stranger, option really shouldn't change much in early boot. > HCTOSYS driver triggers as a late_initcall, so I'd expect you'd get > some output before hitting trouble. > > > > CONFIG_CPU_FREQ_STAT has no effect > > > >With d96ac6f2 reverted: > > > > CONFIG_CPU_FREQ_STAT=n works > > CONFIG_CPU_FREQ_STAT=y does not work > > > >Please see several configurations attached. > > Hrm.. I do wonder if we're seeing something else going on here. It turns out 3.9.4 with d96ac6f2 reverted only fails with CONFIG_CPU_FREQ_STAT=y if I manually enable the Intel PState driver by adding the Thinkpad's IvyBridge processor to the list of supported devices. So this is not part of the regression per se. Best Regards, Jens > > I'll keep digging here, and probably send you some debug patches tomorrow. > > thanks > -john > > > -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html