From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM/ARM64: arch-timer: fix arch_timer_probed logic
Date: Mon, 27 Oct 2014 10:33:18 +0000 [thread overview]
Message-ID: <544E1F6E.5050704@arm.com> (raw)
In-Reply-To: <54463FA2.4070506@linaro.org>
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 <sudeep.holla@arm•com>
>>>> Cc: Stephen Boyd <sboyd@codeaurora•org>
>>>> Cc: Mark Rutland <mark.rutland@arm•com>
>>>> Cc: Daniel Lezcano <daniel.lezcano@linaro•org>
>>>> Cc: Christoffer Dall <christoffer.dall@linaro•org>
>>>> Reported-by: Riku Voipio <riku.voipio@linaro•org>
>>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm•com>
>>>> ---
>>>
>>> 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?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2014-10-27 10:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-15 15:06 [PATCH] ARM/ARM64: arch-timer: fix arch_timer_probed logic Marc Zyngier
2014-10-15 15:28 ` Mark Rutland
2014-10-15 15:49 ` Sudeep Holla
2014-10-21 10:58 ` Daniel Lezcano
2014-10-21 11:07 ` Mark Rutland
2014-10-21 11:12 ` Daniel Lezcano
2014-10-27 10:33 ` Marc Zyngier [this message]
2014-10-27 20:30 ` Thomas Gleixner
2014-10-27 21:52 ` Daniel Lezcano
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