Message-ID: <1513165248.26281.11.camel@suse.com>
Subject: Re: [PATCH] USB: serial: ark3116.c: Remove unused TIOCSSERIAL case
 from ioctl
From: Oliver Neukum <oneukum@suse.com>
To: Mikhail Zaytsev <flashed@mail.ru>
Cc: Johan Hovold <johan@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Date: Wed, 13 Dec 2017 12:40:48 +0100
In-Reply-To: <20171213143142.1c312b57@zaytsev.tver.pg>
References: <20171213123004.4619000a@zaytsev.tver.pg>
         <1513160248.26281.5.camel@suse.com>
         <20171213143142.1c312b57@zaytsev.tver.pg>
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Am Mittwoch, den 13.12.2017, 14:31 +0300 schrieb Mikhail Zaytsev:
> On Wed, 13 Dec 2017 11:17:28 +0100 Oliver Neukum <oneukum@suse.com> wrote:
> 
> > 
> > Am Mittwoch, den 13.12.2017, 12:30 +0300 schrieb Mikhail Zaytsev:
> > > 
> > > +#define RS232_VENDOR 0x6547
> > > +#define RS232_PRODUCT 0x0232
> > > +#define IRDA_VENDOR 0x18ec
> > > +#define IRDA_PRODUCT 0x3118
> > >  
> > >  /* usb timeout of 1 second */
> > >  #define ARK_TIMEOUT 1000
> > >  
> > >  static const struct usb_device_id id_table[] = {
> > > -       { USB_DEVICE(0x6547, 0x0232) },
> > > -       { USB_DEVICE(0x18ec, 0x3118) },         /* USB to IrDA adapter */
> > > +       { USB_DEVICE(RS232_VENDOR, RS232_PRODUCT) },
> > > +       { USB_DEVICE(IRDA_VENDOR, IRDA_PRODUCT) },  /* USB to IrDA adapter */  
> > 
> > Hi,
> > 
> > what is the purpose of this change? It just makes it harder to grep.
> > The constants are arbitrary and they are clearly device IDs.
> 
> The constants are using in several places. 
> I think the names easier to read.

They give you nothing. If you are looking at a vendor ID nothing but the
bare number makes sense. You are just making peoples' life harder when
they have to look up that definition. A symbolic name is fine if it gives
meaning. Even if the information you give is that the value is magic
and therefore not understood. But a vendor ID is an arbitrary yet
meaningful number. There is no point in hiding it.

	Regards
		Oliver