Re: [PATCH] ASoC: simple-card: Fix refcount underflow

From: Kuninori Morimoto
Date: Sun Feb 17 2019 - 20:37:42 EST



Hi Daniel, Mark, again

> > of_get_child_by_name() takes a reference we'll need to drop
> > later so when we substitute in top we need to take a reference
> > as well as just assigning.
> >
> > Without this patch we hit the following error:
> >
> > [ 1.246852] OF: ERROR: Bad of_node_put() on /sound-wm8524
> > [ 1.262261] Hardware name: NXP i.MX8MQ EVK (DT)
> > [ 1.266807] Workqueue: events deferred_probe_work_func
> > [ 1.271950] Call trace:
> > [ 1.274406] dump_backtrace+0x0/0x158
> > [ 1.278074] show_stack+0x14/0x20
> > [ 1.281396] dump_stack+0xa8/0xcc
> > [ 1.284717] of_node_release+0xb0/0xc8
> > [ 1.288474] kobject_put+0x74/0xf0
> > [ 1.291879] of_node_put+0x14/0x28
> > [ 1.295286] __of_get_next_child+0x44/0x70
> > [ 1.299387] of_get_next_child+0x3c/0x60
> > [ 1.303315] simple_for_each_link+0x1dc/0x230
> > [ 1.307676] simple_probe+0x80/0x540
> > [ 1.311256] platform_drv_probe+0x50/0xa0
> >
> > This patch is based on an earlier version posted by Kuninori Morimoto
> > and commit message includes explanations from Mark Brown.
> >
> > https://patchwork.kernel.org/patch/10814255/
> >
> > Reported-by: Vicente Bergas <vicencb@xxxxxxxxx>
> > Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxx>
> > ---
>
> I'm not sure which one is correct in this case
>
> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
>
> or
>
> Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>

And we want to add

Fixes: commit da215354eb55c ("ASoC: simple-card: merge simple-scu-card")