Re: [PATCH 5/5] ASoC: qcom: apq8016_sbc: Allow routing audio through QDSP6

From: Stephan Gerhold <stephan@gerhold.net>
To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Mark Brown <broonie@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Banajit Goswami <bgoswami@codeaurora.org>,
	linux-arm-msm@vger.kernel.org, alsa-devel@alsa-project.org,
	devicetree@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
	~postmarketos/upstreaming@lists.sr.ht
Subject: Re: [PATCH 5/5] ASoC: qcom: apq8016_sbc: Allow routing audio through QDSP6
Date: Fri, 3 Dec 2021 16:09:13 +0100	[thread overview]
Message-ID: <YaozGfiaL2RjeY9W@gerhold.net> (raw)
In-Reply-To: <5c6607cc-ad2a-6f90-e087-78ef3bd39e80@linaro.org>

On Fri, Dec 03, 2021 at 02:52:43PM +0000, Srinivas Kandagatla wrote:
> On 03/12/2021 14:36, Stephan Gerhold wrote:
> > On Fri, Dec 03, 2021 at 10:35:08AM +0000, Srinivas Kandagatla wrote:
> > > I have tested DB410c this use case in the past using similar patch [1].
> > > 
> > 
> > Did you use a different modem DSP firmware? (An older one maybe?)
> 
> It was very old which came with some Android release I guess.
> 

Right, that should be similar to the ones used on MSM8916
smartphones/tablets. I was really glad that the qdsp6 drivers (q6asm,
q6afe, ...) worked without any changes on MSM8916 by the way, thanks a
lot for all your work on them!

> > > > @@ -148,11 +266,16 @@ static const struct snd_soc_dapm_widget apq8016_sbc_dapm_widgets[] = {
> > > >    static int apq8016_sbc_platform_probe(struct platform_device *pdev)
> > > >    {
> > > > +	void (*add_ops)(struct snd_soc_card *card);
> > > >    	struct device *dev = &pdev->dev;
> > > >    	struct snd_soc_card *card;
> > > >    	struct apq8016_sbc_data *data;
> > > >    	int ret;
> > > > +	add_ops = device_get_match_data(&pdev->dev);
> > > > +	if (!add_ops)
> > > > +		return -EINVAL;
> > > 
> > > We will never hit the error case here because without a match we can not
> > > even enter the probe function.
> > > 
> > 
> > Theoretically it's possible to create platform devices through other
> > ways than the device tree (think of old board C files for example).
> > I agree that nobody should do that, but having this check here
> > at least avoids a NULL pointer dereference in this unlikely scenario.
> > 
> > Please let me know if I should remove it anyway, that's fine for me!
> 
> TBH, I don't have very strong opinion on this.
> 

Great, can I assume your Reviewed-by: applies without any changes then?

Thanks,
Stephan