Hi Hiep,
On Fri, Sep 30, 2016 at 11:55 AM, Hiep Cao Minh <cm-hiep@xxxxxxxxxxx> wrote:
> On 09/29/2016 10:40 PM, Geert Uytterhoeven wrote:
>> On Thu, Sep 29, 2016 at 1:03 PM, Hiep Cao Minh <cm-hiep@xxxxxxxxxxx>
>> wrote:
>>> I'd like to report the issue of the CPU operation.
>>> We tested and found it on Lager board at linux-v4.8-rcx.
>>>
>>> The test procedure is the following:
>>>
>>> Confirmation command:
>>>
>>> # cat /proc/interrupts
>>> CPU0
>>> 19: 2509 GIC-0 27 Level arch_timer
>>> 21: 0 GIC-0 36 Level e6050000.gpio
>>> 22: 0 GIC-0 37 Level e6051000.gpio
>>> 23: 0 GIC-0 38 Level e6052000.gpio
>>> 24: 0 GIC-0 39 Level e6053000.gpio
>>> 25: 0 GIC-0 40 Level e6054000.gpio
>>> 26: 0 GIC-0 41 Level e6055000.gpio
>>> 27: 23 GIC-0 101 Level e61f0000.thermal
>>> …”
>>>
>>> This issue appears when we changed the SW8-PIN4 of Lager board.
>>>
>>> SW8-PIN4: ON
>>>
>>> + At linux-v4.7: OK (4 cores work together normally).
>>> + At linux-v4.8-rc2: OK (4 cores work together normally).
>>>
>>> SW8-PIN4: OFF
>>>
>>> + At linux-v4.7: -> OK(4 cores work together normally).
>>> + At linux-v4.8-rc2: -> NG(Only 1 core works).
>>
>> And the kernel prints "Unable to boot CPU%u when MD21 is set", right?
>>
>>> We tried to find out the issued patch and we realize that it happens from
>>> the following patch:
>>> " 043248c Merge tag 'armsoc-dt' of
>>> git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc"
>>
>> The issue you're seeing is due to a combination of commits
>> 5f3bca0db8ac01a7
>> ("ARM: shmobile: apmu: Add APMU DT support via Enable method") and
>> dc378795156d980c ("ARM: dts: r8a7790: Add APMU nodes").
>>
>> When debug mode is enabled (SW8-4 = OFF), trying to boot secondary CPUs
>> may
>> lock up the system after a cold boot, depending of boot load version.
>> Hence
>> we explicitly prohibit that. BTW, this has been the case on Koelsch since
>> commit
>> 277efd30cfc72ec2 ("ARM: shmobile: Check r8a7791 MD21 at SMP boot").
>>
>> Now, does series "[PATCH/RFT 0/4] ARM: shmobile: R-Car Gen2: Allow booting
>> secondary CPU cores in debug mode" (included in all renesas-drivers
>> releases
>> during September) fix it for you?
>
> Thanks for your series patches.
> I have had some problems of receiving post mail from Linux-Renesas Mailing
> List recently.
>
> Could you please forward these series patches to me?
They're included in renesas-drivers.
You can also get them from gitweb at
https://git.kernel.org/cgit/linux/kernel/git/geert/renesas-drivers.git/log/?h=topic/rcar-secondary-booting-in-debug-mode-v1
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
