serial: SERIAL_8250_RUNTIME_UARTS must be <= SERIAL_8250_NR_UARTS

serial: SERIAL_8250_RUNTIME_UARTS must be <= SERIAL_8250_NR_UARTS

[David Vrabel]

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If SERIAL_8250_RUNTIME_UARTS is > SERIAL_8250_NR_UARTS then more serial
ports are registered than we've allocated memory for.  Prevent this by
limiting SERIAL_8250_RUNTIME_UARTS in the serial Kconfig.

Signed-off-by: David Vrabel <dvrabel@arcom.com>
-- 
David Vrabel, Design Engineer

Arcom, Clifton Road           Tel: +44 (0)1223 411200 ext. 3233
Cambridge CB1 7EA, UK         Web: http://www.arcom.com/

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Index: linux-2.6-working/drivers/serial/Kconfig
===================================================================
--- linux-2.6-working.orig/drivers/serial/Kconfig	2006-02-03 14:22:05.000000000 +0000
+++ linux-2.6-working/drivers/serial/Kconfig	2006-02-06 10:17:52.000000000 +0000
@@ -98,6 +98,7 @@
 config SERIAL_8250_RUNTIME_UARTS
 	int "Number of 8250/16550 serial ports to register at runtime"
 	depends on SERIAL_8250
+	range 0 SERIAL_8250_NR_UARTS
 	default "4"
 	help
 	  Set this to the maximum number of serial ports you want
@@ -105,6 +106,9 @@
 	  with the module parameter "nr_uarts", or boot-time parameter
 	  8250.nr_uarts
 
+	  This must be less than or equal to the maximum number of 8250/16550
+	  serial ports supported (SERIAL_8250_NR_UARTS).
+
 config SERIAL_8250_EXTENDED
 	bool "Extended 8250/16550 serial driver options"
 	depends on SERIAL_8250

Re: serial: SERIAL_8250_RUNTIME_UARTS must be <= SERIAL_8250_NR_UARTS

[Yuki Cuss]

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David Vrabel wrote:

>If SERIAL_8250_RUNTIME_UARTS is > SERIAL_8250_NR_UARTS then more serial
>ports are registered than we've allocated memory for.  Prevent this by
>limiting SERIAL_8250_RUNTIME_UARTS in the serial Kconfig.
>
>Signed-off-by: David Vrabel <dvrabel@arcom.com>
>  
>

Is there any real use case for having *less* registered serial ports and 
having some spare?

 - Yuki.


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Re: serial: SERIAL_8250_RUNTIME_UARTS must be <= SERIAL_8250_NR_UARTS

[David Vrabel]

David Vrabel wrote:
> If SERIAL_8250_RUNTIME_UARTS is > SERIAL_8250_NR_UARTS then more serial
> ports are registered than we've allocated memory for.  Prevent this by
> limiting SERIAL_8250_RUNTIME_UARTS in the serial Kconfig.

Nevermind.  I see Russell has already applied an equivilent patch.

David Vrabel
-- 
David Vrabel, Design Engineer

Arcom, Clifton Road           Tel: +44 (0)1223 411200 ext. 3233
Cambridge CB1 7EA, UK         Web: http://www.arcom.com/

Re: serial: SERIAL_8250_RUNTIME_UARTS must be <= SERIAL_8250_NR_UARTS

[Dave Jones]

On Mon, Feb 06, 2006 at 09:42:19PM +1100, Yuki Cuss wrote:
 > David Vrabel wrote:
 > 
 > >If SERIAL_8250_RUNTIME_UARTS is > SERIAL_8250_NR_UARTS then more serial
 > >ports are registered than we've allocated memory for.  Prevent this by
 > >limiting SERIAL_8250_RUNTIME_UARTS in the serial Kconfig.
 > >
 > >Signed-off-by: David Vrabel <dvrabel@arcom.com>
 > > 
 > >
 > 
 > Is there any real use case for having *less* registered serial ports and 
 > having some spare?

Having the ability to build a kernel image which supports many serial ports,
whilst at the same same time when booted on the common-case systems with
two serial ports, not creating so many /dev/ttyS* nodes or sysfs objects
wasting ram that'll never be used or reclaimed.

		Dave