Re: [RFC PATCH] Add bridge driver to connect sensors to CIO2 device via software nodes on ACPI platforms

[Dan Carpenter]

On Thu, Sep 17, 2020 at 01:33:43PM +0300, Sakari Ailus wrote:
> > +static int connect_supported_devices(void)
> > +{
> > +	struct acpi_device *adev;
> > +	struct device *dev;
> > +	struct sensor_bios_data ssdb;
> > +	struct sensor *sensor;
> > +	struct property_entry *sensor_props;
> > +	struct property_entry *cio2_props;
> > +	struct fwnode_handle *fwnode;
> > +	struct software_node *nodes;
> > +	struct v4l2_subdev *sd;
> > +	int i, ret;
> 
> unsigned int i
> 

Why?

For list iterators then "int i;" is best...  For sizes then unsigned is
sometimes best.  Or if it's part of the hardware spec or network spec
unsigned is best.  Otherwise unsigned variables cause a ton of bugs.
They're not as intuitive as signed variables.  Imagine if there is an
error in this loop and you want to unwind.  With a signed variable you
can do:

	while (--i >= 0)
		cleanup(&bridge.sensors[i]);

There are very few times where raising the type maximum from 2 billion
to 4 billion fixes anything.

regards,
dan carpenter