Re: [PATCH] soundwire: stream: add s_rt into slave_rt_list before sdw_config_stream

[Dan Carpenter <dan.carpenter@oracle.com>]

On Thu, Jul 22, 2021 at 07:24:16PM +0800, Dongliang Mu wrote:
> On Thu, Jul 22, 2021 at 7:17 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >
> > On Thu, Jul 22, 2021 at 06:56:11PM +0800, Dongliang Mu wrote:
> > > The commit 48f17f96a817 ("soundwire: stream: fix memory leak in stream
> > > config error path") fixes the memory leak by implicitly freeing the s_rt
> > > object. However, this fixing style is not very good.
> > >
> > > The better fix is to move list_add_tail before sdw_config_stream and
> > > revert the previous commit.
> > >
> > > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> > > ---
> > >  drivers/soundwire/stream.c | 14 +++-----------
> > >  1 file changed, 3 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
> > > index 1a18308f4ef4..66a4ce4f923f 100644
> > > --- a/drivers/soundwire/stream.c
> > > +++ b/drivers/soundwire/stream.c
> > > @@ -1373,19 +1373,11 @@ int sdw_stream_add_slave(struct sdw_slave *slave,
> > >               goto stream_error;
> > >       }
> > >
> > > +     list_add_tail(&s_rt->m_rt_node, &m_rt->slave_rt_list);
> > > +
> > >       ret = sdw_config_stream(&slave->dev, stream, stream_config, true);
> >
> > There some sanity checks on the stream inside sdw_config_stream() so
> > that's probably why we didn't add it until later.  (I don't know the
> > code well, but that's what I would suspect from a glance).
> 
> I think those sanity checks are not much related to list_add_tail.

Yeah.  I can't point to a bug that it causes, it just feels ugly to add
invalid data to the list.

You didn't add Rander to the CC list and he may have had a good reason
to do it that way.

regards,
dan carpenter