Re: [PATCH 09/18] serial: sc16is7xx: add macro for max number of UART ports

From: Hugo Villeneuve
Date: Thu Dec 21 2023 - 11:41:57 EST


On Wed, 20 Dec 2023 17:50:34 +0200
Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> wrote:

> On Tue, Dec 19, 2023 at 12:18:53PM -0500, Hugo Villeneuve wrote:
> > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> >
> > Add macro to hold the maximum number of UART ports per IC/device.
>
> ...
>
> > - if (count < 0 || count > ARRAY_SIZE(irda_port))
> > + if (count < 0 || count > SC16IS7XX_MAX_PORTS)
>
> ARRAY_SIZE() is more robust than this. What if you change to support different
> devices where this won't be as defined?

Hi,
not sure that I understand your point, because SC16IS7XX_MAX_PORTS is
the maximum for all devices supported by this driver. The irda_port
array always has a fixed number of elements set to SC16IS7XX_MAX_PORTS,
even if the device that we are probing has only one port for example.

But I can change it back to ARRAY_SIZE(irda_port) if you want.

>
> > return;
>
> ...
>
> > - if (count < 0 || count > ARRAY_SIZE(mctrl_port))
> > + if (count < 0 || count > SC16IS7XX_MAX_PORTS)
> > return 0;
>
> Ditto.
>
> ...
>
> > + WARN_ON(devtype->nr_uart > SC16IS7XX_MAX_PORTS);
>
> Not sure about this, perhaps it's fine.

This check is only there if we add support for a new device and we
incorrectly set nr_uart to an incorrect value, which will cause other
problems anyway, of course :)

This could be removed.

Hugo Villeneuve