From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Mon, 27 Oct 2014 22:52:25 +0100 Subject: [PATCH] ARM/ARM64: arch-timer: fix arch_timer_probed logic In-Reply-To: References: <1413385580-23317-1-git-send-email-marc.zyngier@arm.com> <54463C55.8010209@linaro.org> <20141021110728.GD15293@leverpostej> <54463FA2.4070506@linaro.org> <544E1F6E.5050704@arm.com> Message-ID: <544EBE99.6080300@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/27/2014 09:30 PM, Thomas Gleixner wrote: > On Mon, 27 Oct 2014, Marc Zyngier wrote: >> Hi Daniel, >> >> On 21/10/14 12:12, Daniel Lezcano wrote: >>> On 10/21/2014 01:07 PM, Mark Rutland wrote: >>>> Hi Daniel, >>>> >>>> On Tue, Oct 21, 2014 at 11:58:29AM +0100, Daniel Lezcano wrote: >>>>> On 10/15/2014 05:06 PM, Marc Zyngier wrote: >>>>>> Commit c387f07e6205 (clocksource: arm_arch_timer: Discard unavailable >>>>>> timers correctly) changed the way the driver makes sure both the memory >>>>>> and system-register timers have been probed before finalizing the probing. >>>>>> >>>>>> There is a interesting flaw in this logic that leads to this final step >>>>>> never to be executed. Things seems to work pretty well until something >>>>>> actually needs the data that is produced during this final stage. >>>>>> >>>>>> For example, KVM explodes on the first run of a guest when executed on >>>>>> a platform that has both memory and sysreg nodes (Juno, for example). >>>>>> >>>>>> Just fix the damned logic, and enjoy booting VMs again. >>>>>> >>>>>> Tested on a Juno system. >>>>>> >>>>>> Cc: Sudeep Holla >>>>>> Cc: Stephen Boyd >>>>>> Cc: Mark Rutland >>>>>> Cc: Daniel Lezcano >>>>>> Cc: Christoffer Dall >>>>>> Reported-by: Riku Voipio >>>>>> Signed-off-by: Marc Zyngier >>>>>> --- >>>>> >>>>> Applied to my tree. Also for -next. >>>> >>>> Is this going to hit -rc2? This was a regression introduced in -rc1. >>>> >>>> Without this fix we've also lost our high precision sched_clock on arm64 >>>> platforms. >>>> >>> >>> Sure. >>> >>> Thomas or Ingo, >>> >>> is it possible to update the tip/urgent branch, so I can send the fixes >>> against 3.18-rc1 ? >> >> Any update on this? -rc2 has landed, but arm/arm64 timers are still in a >> rather bad shape. Can this please be merged as an urgent fix? > > Daniel, timers/urgent is on rc1 already. Please send your pull request. Hi Thomas, This pull request for one patch contains a fix for ARM/ARM64 platform: * Marc Zyngier fixed the probe logic for the ARM architected timers. Thanks -- Daniel The following changes since commit 59aa896db80479dec29f471a7ca2b9eeeeb7d38e: ARM/ARM64: arch-timer: fix arch_timer_probed logic (2014-10-26 20:50:00 +0100) are available in the git repository at: http://git.linaro.org/people/daniel.lezcano/linux.git clockevents/3.18-fixes for you to fetch changes up to 59aa896db80479dec29f471a7ca2b9eeeeb7d38e: ARM/ARM64: arch-timer: fix arch_timer_probed logic (2014-10-26 20:50:00 +0100) -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog