Re: Serial Driver Name Question (kernels 2.4.x)

[Ivan Passos <ivan@cyclades.com>]

Andrew Morton wrote:
> 
> Richard, can we please get this wrapped up?
> 
> My preferred approach is to change the driver naming scheme
> so that we don't have to put printf control-strings everywhere.
> We can remove a number of ifdefs that way.
> 
> So for serial.c:
> 
> --- linux-2.4.18-pre2/drivers/char/tty_io.c     Mon Jan  7 16:48:02 2002
> +++ linux-akpm/drivers/char/tty_io.c    Mon Jan  7 20:56:38 2002
> @@ -193,10 +193,13 @@ _tty_make_name(struct tty_struct *tty, c
> 
>         if (!tty) /* Hmm.  NULL pointer.  That's fun. */
>                 strcpy(buf, "NULL tty");
> -       else
> -               sprintf(buf, name,
> -                       idx + tty->driver.name_base);
> -
> +       else {
> +#ifdef CONFIG_DEVFS_FS
> +               sprintf(buf, "%s/%d", name, idx + tty->driver.name_base);
> +#else
> +               sprintf(buf, "%s%d", name, idx + tty->driver.name_base);
> +#endif
> +       }
>         return buf;
>  }
> 
> --- linux-2.4.18-pre2/drivers/char/serial.c     Mon Jan  7 16:48:02 2002
> +++ linux-akpm/drivers/char/serial.c    Mon Jan  7 20:58:09 2002
> @@ -5387,7 +5387,7 @@ static int __init rs_init(void)
>         serial_driver.driver_name = "serial";
>  #endif
>  #if (LINUX_VERSION_CODE > 0x2032D && defined(CONFIG_DEVFS_FS))
> -       serial_driver.name = "tts/%d";
> +       serial_driver.name = "tts";
>  #else
>         serial_driver.name = "ttyS";
>  #endif

This doesn't cover all the drivers, because the definition for devfs 
is that the standard serial "translates" 'ttyS' to 'tts/', and other 
serial drivers "translate" 'ttyN' (where 'N' can be several 
different letters -- e.g. 'C' for Cyclades, 'R' for Comtrol, 'X' for 
Specialix, 'D' for Digi, etc.) to 'tts/N' (so that standard serial 
and other serial devices can share the same devfs directory).

So, I believe the best way to solve this would be:

drivers/char/tty_io.c:
@@ -193,10 +193,13 @@ _tty_make_name(struct tty_struct *tty, c

        if (!tty) /* Hmm.  NULL pointer.  That's fun. */
                strcpy(buf, "NULL tty");
        else
-               sprintf(buf, name,
-                       idx + tty->driver.name_base);
+               sprintf(buf, "%s%d", name, idx + tty->driver.name_base);
 
        return buf;
 }

drivers/char/serial.c:
@@ -5387,7 +5387,7 @@ static int __init rs_init(void)
        serial_driver.driver_name = "serial";
 #endif
 #if (LINUX_VERSION_CODE > 0x2032D && defined(CONFIG_DEVFS_FS))
-       serial_driver.name = "tts/%d";
+       serial_driver.name = "tts/";
 #else
        serial_driver.name = "ttyS";
 #endif


And then, for instance, for the Cyclades driver, we'd use:

#ifdef CONFIG_DEVFS_FS
	cy_serial_driver.name = "tts/C";
#else
	cy_serial_driver.name = "ttyC";
#endif

, and let's not forget the callout devices (which follow a similar 
rule):

#ifdef CONFIG_DEVFS_FS
	cy_callout_driver.name = "cua/C";
#else
	cy_callout_driver.name = "cub";
#endif

This would apply for other drivers as well, just replacing the 'C' 
by the proper letter.

So, what do you think?!?!?

Later,
-- 
Ivan Passos							 -o)
Integration Manager, Cyclades	- http://www.cyclades.com	 /\\
Project Leader, NetLinOS	- http://www.netlinos.org	_\_V
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