From mboxrd@z Thu Jan 1 00:00:00 1970 From: Koro Chen Subject: Re: [alsa-devel] [RFC PATCH] ASoC: Modify check condition of multiple bindings of components Date: Tue, 13 Oct 2015 22:18:22 +0800 Message-ID: <1444745902.26493.2.camel@mtksdaap41> References: <1444743477-48819-1-git-send-email-koro.chen@mediatek.com> <561D0AA9.5080702@metafoo.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <561D0AA9.5080702@metafoo.de> Sender: linux-kernel-owner@vger.kernel.org To: Lars-Peter Clausen Cc: broonie@kernel.org, perex@perex.cz, tiwai@suse.de, lgirdwood@gmail.com, alsa-devel@alsa-project.org, srv_heupstream@mediatek.com, s.hauer@pengutronix.de, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, p.zabel@pengutronix.de, linux-arm-kernel@lists.infradead.org List-Id: linux-mediatek@lists.infradead.org On Tue, 2015-10-13 at 15:44 +0200, Lars-Peter Clausen wrote: > On 10/13/2015 03:37 PM, Koro Chen wrote: > > The patch "ASoC: Prevent components from being bound to multiple cards" > > adds check to prevent multiple cards from using the same component. > > However, snd_soc_register_platform() or snd_soc_register_codec() will > > also create components, and sharing the same platform by multiple cards > > is then refused. This happens with a platform having multiple > > independent DAIs that share the same DMA controller. > > > > Relax the condition by checking component->registered_as_component, > > which is only true in case of snd_soc_register_component() and > > will be false for components created by snd_soc_register_platform() > > or snd_soc_register_codec(). > > Binding a component to multiple cards results in internal data structure > corruption, regardless of whether it is a raw component, CODEC or platform, > which is why the check was added. So the proposed change wont work. > Thanks for your comment. Is it possible to share an example of how the data structure will be corrupted? So I can study into this further. > > > > Signed-off-by: Koro Chen > > --- > > sound/soc/soc-core.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c > > index 42575b0..eca169a 100644 > > --- a/sound/soc/soc-core.c > > +++ b/sound/soc/soc-core.c > > @@ -1106,7 +1106,8 @@ static int soc_probe_component(struct snd_soc_card *card, > > return 0; > > > > if (component->card) { > > - if (component->card != card) { > > + if (component->card != card && > > + component->registered_as_component) { > > dev_err(component->dev, > > "Trying to bind component to card \"%s\" but is already bound to card \"%s\"\n", > > card->name, component->card->name); > > > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@alsa-project.org > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel