Re: [BISECTED REGRESSION] v4.8-rc: DT/OCTEON driver probing broken

From: Aaro Koskinen
Date: Sun Aug 28 2016 - 08:22:58 EST


Hi,

On Sun, Aug 28, 2016 at 12:34:06PM +0200, Thorsten Leemhuis wrote:
> Lo! Kefeng, below report made it to the list of regression for 4.8, but
> afaics nothing happened after the initial report. Is there maybe some
> reason why it shouldn't be on the list of regressions at all? Or was the
> problem discussed elsewhere? Or is it even fixed already? I noticed
> https://git.kernel.org/torvalds/c/fc520f8b4f (of/platform: disable the
> of_platform_default_populate_init() for all the ppc board), but that
> change is PPC specific.

There is a fix proposal here:

https://patchwork.linux-mips.org/patch/14041/

There is still few other boards remaining that use of_platform_bus_probe()
from device_initcall, but who knows, maybe they are not affected.

arch/microblaze/kernel/platform.c
arch/mips/mti-malta/malta-dt.c
arch/mips/netlogic/xlp/dt.c
arch/x86/platform/olpc/olpc_dt.c

A.

> On 16.08.2016 17:00, Aaro Koskinen wrote:
> > Hi,
> >
> > Commit 44a7185c2ae6 ("of/platform: Add common method to populate default
> > bus") added new arch_initcall of_platform_default_populate_init() that
> > will be called before device_initcall octeon_publish_devices(). Now the
> > of_platform_bus_probe() called in octeon_publish_devices() is apparently
> > doing nothing:
> >
> > [ 52.331353] calling octeon_publish_devices+0x0/0x14 @ 1
> > [ 52.331358] OF: of_platform_bus_probe()
> > [ 52.331362] OF: starting at: /
> > [ 52.331378] OF: of_platform_bus_create() - skipping /soc@0, already populated
> > [ 52.331394] initcall octeon_publish_devices+0x0/0x14 returned 0 after 29 usecs
> >
> > This also means that USB etc. won't get probed.
> >
> > Any ideas what would be the proper fix for this? Changing
> > octeon_publish_devices() to arch_initcall seems to work but that may be
> > a bit hackish... Also, there might be also other MIPS boards affected
> > (arch/mips/netlogic/xlp/dt.c, arch/mips/mti-malta/malta-dt.c).
> >
> > A.
> >
> > http://news.gmane.org/find-root.php?message_id=20160816150056.GD18731%40ak-desktop.emea.nsn-net.net
> > http://mid.gmane.org/20160816150056.GD18731%40ak-desktop.emea.nsn-net.net
> >
>