bcm4708-smartrg-sr400ac boot failures in next-20150918+

[Tyler Baker]

On 11 October 2015 at 15:49, Hauke Mehrtens <hauke at hauke-m.de> wrote:
> Adding the arm List.
>
> On 10/01/2015 11:46 PM, Hauke Mehrtens wrote:
>> On 10/01/2015 07:50 PM, Tyler Baker wrote:
>>> Hi Hauke, Rafal,
>>>
>>> The kernelci.org bot has been reporting complete boot failures[1]
>>> since next-20150918. I've bisected[2] the issue and found "ARM:
>>> 8422/1: enable imprecise aborts during early kernel startup" is the
>>> offending patch. Reverting this on top of -next fixes the boot issue.
>>>
>>> Apologies for sending this off list, but I want to make sure you can
>>> confirm this issue before we raise it.
>>>
>>> Cheers,
>>>
>>> Tyler
>>>
>>> [1] http://kernelci.org/boot/bcm4708-smartrg-sr400ac/
>>> [2] http://hastebin.com/mirunerobi.vhdl
>>>
>> Hi Tyler,
>>
>> Thanks for the info, the broken bootloader causes some problems when
>> booting the kernel, we already had to ignore some exceptions. I will
>> look into this at the weekend.
>>
>> Hauke
>>
> Hi,
>
> The commit "ARM: 8422/1: enable imprecise aborts during early kernel
> startup" breaks bcm53xx devices with a broken boot loader, this is a
> regression. There are probably millions of these devices shipped with
> this boot loader called CFE.
> For BCM53xx we install a fault handler in the init_early callback of
> DT_MACHINE_START to ignore the faults produced by the boot loader in
> http://lxr.free-electrons.com/source/arch/arm/mach-bcm/bcm_5301x.c#L40 ,
> but init_early is called after local_abt_enable() gets called and this
> causes a kernel panic because of any unhandled CPU fault. The reserve()
> callback in DT_MACHINE_START was the only callback I could find which
> gets called before local_abt_enable(), should I move the code which
> installs the fault handler there?
>
> This is causing the problems in kernelci with linux next kernels on this
> board: http://kernelci.org/boot/bcm4708-smartrg-sr400ac/

Adding Russell, and Lucas to CC as they may be interested in this thread.

Cheers,

Tyler