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

From: Daniel Baluta
Date: Mon Feb 18 2019 - 02:06:28 EST


On Mon, 2019-02-18 at 10:37 +0900, Kuninori Morimoto wrote:
> 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://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fpatch%2F10814255%2F&data=02%7C01%7Cdaniel.baluta%40nxp.com%7Ced1b7adc66a546c1bb4608d69541aaf8%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636860506617983174&sdata=hTsurDLdtLAtTw0a5v%2FrSsleSawAP2yiVPl87%2BHCzTI%3D&reserved=0
> > >
> > > 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")
>

Thanks! I thought about adding this but the current patch will not
cleanly apply because of:

2d01a84605a55c ("ASoC: simple-card: reduce naming prefix")