[PATCH] ARM: exynos_defconfig: disable CONFIG_EXYNOS5420_MCPM; not stable

[Olof Johansson]

On Mon, Nov 24, 2014 at 5:35 PM, Kevin Hilman <khilman at kernel.org> wrote:
> On Mon, Nov 24, 2014 at 4:25 PM, Olof Johansson <olof at lixom.net> wrote:
>> On Mon, Nov 24, 2014 at 11:51 AM, Kevin Hilman <khilman at kernel.org> wrote:
>>> Kukjin,
>>>
>>> On Mon, Nov 10, 2014 at 11:35 AM, Kevin Hilman <khilman at kernel.org> wrote:
>>>> Kukjin Kim <kgene at kernel.org> writes:
>>>>
>>>>> Kevin Hilman wrote:
>>>>>>
>>>>>> From: Kevin Hilman <khilman at linaro.org>
>>>>>>
>>>>>> The option CONFIG_EXYNOS5420_MCPM is causing imprecise external aborts
>>>>>> during boot testing, causing various userspace startup failures.
>>>>>>
>>>>>> Disable until it has gotten more testing.
>>>>>>
>>>>>> Cc: Kukjin Kim <kgene.kim at samsung.com>,
>>>>>> Cc: Javier Martinez Canillas <javier.martinez at collabora.co.uk>,
>>>>>> Cc: Sachin Kamat <sachin.kamat at samsung.com>,
>>>>>> Cc: Doug Anderson <dianders at chromium.org>,
>>>>>> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>,
>>>>>> Cc: Krzysztof Kozlowski <k.kozlowski at samsung.com>,
>>>>>> Cc: Tushar Behera <tushar.behera at linaro.org>,
>>>>>> Cc: stable at vger.kernel.org # v3.17+
>>>>>> Signed-off-by: Kevin Hilman <khilman at linaro.org>
>>>>>> ---
>>>>>> This has been reported by a few people[1], but not investigated or fixed, so it's
>>>>>> time to disable this feature until it can be fixed.
>>>>>>
>>>>> Hi Kevin,
>>>>>
>>>>> Yeah I agree with your opinion.
>>>>>
>>>>> But as you can see my tree, I've queued regarding mcpm patches for 3.19 will
>>>>> be shown in -next in this weekend.
>>>>
>>>> Which of the recently queued patches are expected to address the
>>>> imprecise abort issue?  I'd be happy to test them out.
>>>
>>> Exynos5 MCPM is still broken in linux-next and still causing an imprecise abort.
>>>
>>> What is the status of $SUBJECT patch?
>>>
>>>>> Anyway let me apply this into -fixes and
>>>>> then let's enable after test its functionality in -next in a couple of days.
>>>>
>>>> Yes, I think this needs to be applied until these aborts are understood
>>>> and fixed.
>>>
>>> Is anyone at Samsung actually looking into these MCPM issues?
>>
>> Hi Kevin,
>>
>> What hardware are you having problems with? 5420 or 5422/5800?
>
> Yes.  :)
>
> exynos5420-arndale-octa:
> http://storage.armcloud.us/kernel-ci/mainline/v3.18-rc6/arm-exynos_defconfig/boot-exynos5420-arndale-octa.html
> exynos5422-odroid-xu3:
> http://storage.armcloud.us/kernel-ci/mainline/v3.18-rc6/arm-exynos_defconfig/boot-exynos5422-odroid-xu3.html
>
> My boot tests seem to pass fine because I have such a minimal
> userspace, but Tyler Baker reported that with a "real" userspace, he
> can't boot to a shell:
>
>   http://lists.infradead.org/pipermail/linux-arm-kernel/2014-September/286203.html

I'm not surprised that 5420 has issues, but I have not seen any
external aborts on neither Chromebook that I have in my farm.

Sounds like the secondary cpus should be disabled on those device
trees instead, doesn't it?


-Olof