Re: GEN2:Lager: Only 1 core works when turning off the SW8-PIN4

[Hiep Cao Minh <cm-hiep@jinso.co.jp>]

Hi Geert,

Thanks for your reply!

On 09/29/2016 10:40 PM, Geert Uytterhoeven wrote:
> Hi Hiep,
>
> On Thu, Sep 29, 2016 at 1:03 PM, Hiep Cao Minh <cm-hiep@jinso.co.jp> 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?

Thank you!.
Jinso/Linux-Team
Hiep.