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Date: Wed, 21 Feb 2024 18:22:44 +0000
From: Matthias Kaehlcke <mka@chromium.org>
To: Javier Carrasco <javier.carrasco@wolfvision.net>
Cc: Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-sound@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
	Matthias Kaehlcke <matthias@kaehlcke.net>
Subject: Re: [PATCH v3 1/7] usb: misc: onboard_hub: rename to onboard_dev
Message-ID: <ZdY_dBZyqiys0gf_@google.com>
References: <20240206-onboard_xvf3500-v3-0-f85b04116688@wolfvision.net>
 <20240206-onboard_xvf3500-v3-1-f85b04116688@wolfvision.net>
 <ZcJynrwp7zcs-aIT@google.com>
 <36b813ad-fdcb-495b-9d27-3573b6177831@wolfvision.net>
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In-Reply-To: <36b813ad-fdcb-495b-9d27-3573b6177831@wolfvision.net>

On Tue, Feb 13, 2024 at 11:36:25AM +0100, Javier Carrasco wrote:
> Hi Matthias,
> 
> On 06.02.24 18:55, Matthias Kaehlcke wrote:
> > Hi Javier,
> >
> > a few comments inline
> >
> > On Tue, Feb 06, 2024 at 02:59:29PM +0100, Javier Carrasco wrote:
> >> +static struct onboard_dev *_find_onboard_dev(struct device *dev)
> >> +{
> >> +	struct platform_device *pdev;
> >> +	struct device_node *np;
> >> +	struct onboard_dev *onboard_dev;
> >> +
> >> +	pdev = of_find_device_by_node(dev->of_node);
> >> +	if (!pdev) {
> >> +		np = of_parse_phandle(dev->of_node, "peer-hub", 0);
> >> +		if (!np) {
> >> +			dev_err(dev, "failed to find device node for peer hub\n");
> >> +			return ERR_PTR(-EINVAL);
> >> +		}
> >> +
> >> +		pdev = of_find_device_by_node(np);
> >> +		of_node_put(np);
> >> +
> >> +		if (!pdev)
> >> +			return ERR_PTR(-ENODEV);
> >> +	}
> >
> > The above branch should probably be guarded by 'if (!onboard_dev->pdata->is_hub)',
> > this is also a change for ""usb: misc: onboard_dev: add support for non-hub devices"
> >
> I am not sure how to guard the branch like that because onboard_dev is
> retrieved by means of pdev->dev, which is not available if
> of_find_device_by_node returns NULL. The non-hub device will not have a
> peer-hub property according to its bindings anyway, right?

Right, onboard_dev isn't available yet at that point, my bad. I thought it
would be nice to clearly separate the hub related logic from other devices,
but that isn't an option in this case.