Re: [GIT PULL] On-demand device probing

From: Olof Johansson
Date: Mon Oct 19 2015 - 12:53:23 EST


On Sat, Oct 17, 2015 at 8:19 AM, Rob Herring <robh+dt@xxxxxxxxxx> wrote:
> On Fri, Oct 16, 2015 at 4:23 PM, Olof Johansson <olof@xxxxxxxxx> 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@xxxxxxxxxxxxx> 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
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