Re: ARM Juno r1 + CONFIG_PROVE_LOCKING=y => boot failure

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hi Sudeep,

On 11.10.2019 16:42, Sudeep Holla wrote:
> On Fri, Oct 11, 2019 at 02:43:54PM +0100, Sudeep Holla wrote:
>> On Fri, Oct 11, 2019 at 03:15:32PM +0200, Marek Szyprowski wrote:
>>> Hi Sudeep
>>>
>>> On 11.10.2019 15:10, Sudeep Holla wrote:
>>>> On Fri, Oct 11, 2019 at 03:02:42PM +0200, Marek Szyprowski wrote:
>>>>> Hi James,
>>>>>
>>>>> On 11.10.2019 12:38, James Morse wrote:
>>>>>> Hi guys,
>>>>>>
>>>>>> On 11/10/2019 11:05, Sudeep Holla wrote:
>>>>>>> On Fri, Oct 11, 2019 at 11:26:04AM +0200, Marek Szyprowski wrote:
>>>>>>>> Recently I've got access to ARM Juno R1 board and did some tests with
>>>>>>>> current mainline kernel on it. I'm a bit surprised that enabling
>>>>>>>> CONFIG_PROVE_LOCKING causes a boot failure on this board. After enabling
>>>>>>>> this Kconfig option, I get no single message from the kernel, although I
>>>>>>>> have earlycon enabled.
>>>>>>> I don't have Juno R1 but I tried defconfig + CONFIG_PROVE_LOCKING and
>>>>>>> it boots fine.
>>>>>> I just tried this on my r1, v5.4-rc1 with this configuration worked just fine.
>>>>>>
>>>>>> My cmdline is:
>>>>>> | root=/dev/sda6 loglevel=9 earlycon=pl011,0x7ff80000 hugepagesz=2M hugepages=512
>>>>>> | crashkernel=1G console=ttyAMA0 resume=/dev/sda2 no_console_suspend efi=debug
>>>>>>
>>>>> That is a bit strange. Here is a boot log from v5.4-rc1 with pure
>>>>> defconfig: https://paste.debian.net/1105851/
>>>>>
>>>> I see from the boot log that both Image.gz and dtb being loaded at the
>>>> same address 0x82000000, will u-boot uncompress it elsewhere after loading
>>>> it ? Just for my understanding.
>>> tftp downloads Image.gz to 0x82000000, then decompress it to
>>> $kernel_addr to save transfer time
>>>
>>> my bootcmd is:
>>>
>>> tftp ${fdt_addr} juno/Image.gz; unzip ${fdt_addr} ${kernel_addr}; tftp
>>> ${fdt_addr} juno/juno-r1.dtb; booti ${kernel_addr} - ${fdt_addr};
>>>
> If your ${kernel_addr}=0x80000000 or within first 32MB, then it will override
> DTB with the image size I had(35MB). Even if kernel fits 32MB, there is a
> chance that .bss lies beyond 32MB and it will be cleared during boot resulting
> in DTB corruption(Andre P reminded me this)
>
> Can you try setting $${fdt_addr} to 0x84000000 to begin with ?

Right, my fault. Changing fdt_addr to something higher than the default 
0x82000000 fixed the boot issue. I wonder how I missed that, as I was 
convinced that there is enough space for the kernel image. Sorry for the 
noise...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland