From: sudeep.holla@arm•com (Sudeep Holla)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM/ARM64: arch-timer: fix arch_timer_probed logic
Date: Wed, 15 Oct 2014 16:49:04 +0100 [thread overview]
Message-ID: <543E9770.3010103@arm.com> (raw)
In-Reply-To: <20141015152823.GH20034@leverpostej>
On 15/10/14 16:28, Mark Rutland wrote:
> On Wed, Oct 15, 2014 at 04:06:20PM +0100, 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).
>
> As far as I can tell, the logic is flawed for all cases except two
> functional nodes that we manage to probe.
>
Agreed, it's my mistake. I inverted the logic incorrectly when I moved
it to a function while adding of_node_put in v2 of the patch.
I think wrong DTB got picked up when I tested this. I am sorry for that.
>>
>> 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>
>
> The new logic makes sense to me, so:
>
> Acked-by: Mark Rutland <mark.rutland@arm•com>
Acked-by: Sudeep Holla <sudeep.holla@arm•com>
Tested-by: Sudeep Holla <sudeep.holla@arm•com>
(This time tested all possible case)
Regards,
Sudeep
next prev parent reply other threads:[~2014-10-15 15:49 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 [this message]
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
2014-10-27 20:30 ` Thomas Gleixner
2014-10-27 21:52 ` Daniel Lezcano
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