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Date: Tue, 14 May 2024 14:33:31 +0000
From: Sakari Ailus <sakari.ailus@linux.intel.com>
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Bingbu Cao <bingbu.cao@intel.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Hans de Goede <hdegoede@redhat.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Daniel Scally <dan.scally@ideasonboard.com>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: Re: [PATCH v2] media: ipu-bridge: fix error code in ipu_bridge_init()
Message-ID: <ZkN2Ow6hASmKvHlz@kekkonen.localdomain>
References: <f468c4ac-0629-41b5-b5d1-e26f70e44800@moroto.mountain>
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In-Reply-To: <f468c4ac-0629-41b5-b5d1-e26f70e44800@moroto.mountain>

Hi Dan,

On Fri, May 10, 2024 at 06:43:31PM +0300, Dan Carpenter wrote:
> Return -EINVAL if "bridge->n_sensors == 0".  Don't return success.
> 
> Fixes: 881ca25978c6 ("media: ipu3-cio2: rename cio2 bridge to ipu bridge and move out of ipu3")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> v2: style change
> 
>  drivers/media/pci/intel/ipu-bridge.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/pci/intel/ipu-bridge.c b/drivers/media/pci/intel/ipu-bridge.c
> index 61750cc98d70..44a9d9c15b05 100644
> --- a/drivers/media/pci/intel/ipu-bridge.c
> +++ b/drivers/media/pci/intel/ipu-bridge.c
> @@ -839,9 +839,14 @@ int ipu_bridge_init(struct device *dev,
>  		bridge->data_lanes[i] = i + 1;
>  
>  	ret = ipu_bridge_connect_sensors(bridge);
> -	if (ret || bridge->n_sensors == 0)
> +	if (ret)
>  		goto err_unregister_ipu;
>  
> +	if (bridge->n_sensors == 0) {
> +		ret = -EINVAL;
> +		goto err_unregister_ipu;
> +	}

This would return an error if there are no sensors.

Neither IPU3-CIO2 or IPU6 ISYS drivers should be of any functional use
without sensors. But the power states of the devices could be affected by
this: the drivers should power off these devices but without drivers they
maybe left powered on. I haven't made any measurements though.

> +
>  	dev_info(dev, "Connected %d cameras\n", bridge->n_sensors);
>  
>  	fwnode = software_node_fwnode(&bridge->ipu_hid_node);

-- 
Kind regards,

Sakari Ailus