[GIT PULL] On-demand device probing

[Olof Johansson]

On Sat, Oct 17, 2015 at 8:19 AM, Rob Herring <robh+dt at kernel.org> wrote:
> On Fri, Oct 16, 2015 at 4:23 PM, Olof Johansson <olof at lixom.net> wrote:
>> Hi,
>>
>> I've bisected boot failures in next-20151016 down to patches in this branch:
>>
>> On Thu, Oct 15, 2015 at 4:42 AM, Tomeu Vizoso
>> <tomeu.vizoso at collabora.com> wrote:
>>> Tomeu Vizoso (20):
>>>       driver core: handle -EPROBE_DEFER from bus_type.match()
>>
>> The machine it happened on was OMAP5UEVM:
>>
>> http://arm-soc.lixom.net/bootlogs/next/next-20151016/omap5uevm-arm-omap2plus_defconfig.html
>
> So this one is because the MMC node numbering changed. I don't know
> how to fix that other than with aliases, but that doesn't solve
> backwards compatibility.

Yep, aliases will take care of it in this case. This is where -next
fills a great purpose, we can make sure we get those aliases added in
before the patches go in.

>> But I've also seen it on tegra2, that one bisected down to:
>>
>>>      regulator: core: Probe regulators on demand
>>
>> http://arm-soc.lixom.net/bootlogs/next/next-20151016/seaboard-arm-multi_v7_defconfig.html
>
> This one you need a rootwait I think. The MMC scanning is not
> guaranteed to be done before the rootfs mounting AFAIK. There may be
> other problems, but we can't see them since it panics.

Embarrassing, I almost always do this and I'm surprised this machine
has been this stable without it.


-Olof